Venomous and Underrated: Paralysis Ticks and Undersea Pricks

This post is the second in a two-part series on particularly potent venoms found in organisms not commonly renowned for their chemical fortitude. Part 1, which explored the stings of ants and wasps, can be found here.

The fact that there are a number of hymenopterans (ants, bees, and wasps) that have particularly nasty venom isn’t exactly a shocking revelation; these insects are solidly associated with their aggravation-driven stings and their painful side-effects. The degree to which some of these stings can pack a blow may be not well-appreciated, but the general public consciousness is already quite unhappily familiar with how hymenopterans liberally dispense venoms into any and all soft, unguarded tissues like it’s their goddamn job. However, there are entire groups of animals that are worryingly, intimidatingly venomous that are hardly ever even thought of as being venomous in the first place. Yet, these animals have the same chemical gift that has brought infamy to spiders, snakes, and scorpions the world over…that same Midas touch….that is, if everything King Midas touched was suddenly gripped by unbearable, electric agony and shit all over itself in screaming, fitful anguish until it died.

The first of these are animals most folks hardly think about outside the contexts of disease transmission, things that might make the family dog very unhappy, and Leno-chinned superheros in sky blue spandex. It’s likely that only if you spend substantial time in rural areas during warm weather months does this parasite ever clamber into your overall awareness. Yes, I’m talking of course about the glorious, unflinchingly, universally revered tick.

Ticks are the notorious, unabashed gourmands of the arachnid world, partaking heavily and exclusively in the reddest of wines there is; blood. Ticks get all of their nutritional requirements from the blood of vertebrates, and require blood meals to produce offspring and to transition from one developmental stage to the next, ‘leveling up’ like Mario curb stomping a mushroom. To feed on this precious elixir, ticks have to somehow pump it out of their hosts. They do this by tearing open the outer layers of skin with paired cutting mouthparts, and by plunging their “hypostome”, a rugged, practically unbreakable spear-like component of their mouth, deep into the skin. “Spear-like” really doesn’t do this anatomical atrocity justice as a descriptor, actually. Scaled up to nightmarish, non-microscopic proportions, it resembles the depraved union of Klingon weapon and a sex toy designed by a cruel and angry god. From another angle, it looks like someone glued a hedge-trimmer on a mouth harp.

Although, it might need a little tuning. It looks a bit sharp.

Compared to things like mosquitoes and leeches, ticks aren’t nearly as gentle and considerate about making their non-consensual withdrawals from the blood bank. Rather than expertly piercing a blood vessel, and cleanly sucking up the payload through straw-like mouthparts, ticks employ a markedly inelegant strategy. The sharp mouthparts are used to saw into the skin horizontally, providing an access tunnel for the barbed hypostome. They sweep through and clear-cut tangles of tiny blood vessels like a weed-trimmer shredding a roadside thicket. The rent vessels spring forth with their delicious contents, and the flood generates a pool just under the surface of the skin from which the tick can slurp up its meal through the hypostome.

When the peckish parasite penetrates through the outermost epidermal layers of skin, that’s when the real fun begins, and the venom comes into play. Ticks are indeed venomous animals, and rely on a medley of saliva-bound toxins they inject into the wound site to keep the feeding process running smoothly. Tick venom is complex, with each component toxin targeting a specific physiological process, the multitude of them adding up to create a gestalt effect geared towards keeping the gravy train flowing into Tick Town, and the host’s body completely oblivious that something is amiss. Tick venom is very good at keeping the nutritive river running; anti-coagulants, thrombin inhibitors, small proteins that screw with platelet plug formation (a key part of clotting), and vasodilators (molecules that help widen the piping in your circulatory system) all make the host bleed like Russian royalty, growing the blood reservoir below the skin and allowing the tick to feed uninterrupted. The venom also has a whole host of anti-inflammatory components that work to shut down localized immune response to the bite and all the saliva being pumped in. These toxins are a molecular invisibility cloak, and allow the tick’s feeding to fly under the radar of the host’s immune system. This, in turn, allows the tick to guzzle on the good stuff, anchored in place, for a LONG time compared to other blood-sucking animals (we’re talking a week or more in some untreated cases). Female ticks are especially gluttonous, packing away ten times their original body mass in blood. At the end of a blood meal they, much like Marlon Brando in that 90s remake of “The Island of Dr. Moreau”, are left turgid and bloated far beyond any resemblance to their former svelte selves.

Left: Me before visiting Chipotle
Right: Me after visiting Chipotle

It is through their feeding and injection of potent salivary chemicals that ticks manage to serve as vectors for a multitude of diseases. More than a dozen disease-causing microorganisms (and growing) hitch a ride inside ticks and infect the animals they bite via their chauffeur’s venomous spit. Some of them are familiar…and horrifying; Lyme disease, Rocky Mountain spotted fever, and Colorado tick fever are just a few. Many of these illnesses are knock-you-on-your-ass debilitating, and for this reason, the real health concerns of tick bites don’t come from the venom itself, but from whatever bacterial or viral horrors were tagging along. Ticks are dangerous venomous animals in the same way that mosquitoes are, simply by being the filthiest, most pestilence-ridden vampires this side of an unregulated Transylvanian bordello.

“But hold on now,” I hear you protest. “What the fuck is this tricky-dicky bullshit? Wasn’t this post about ‘surprisingly venomous’ critters and not ‘surprisingly disingenuous list entries based on a technicality’?”

Well, take a seat, unabashedly displeased reader, and get ready to untwist your knickers, because there’s another aspect of tick venom that packs a punch well beyond the fact that the stuff is basically a pathogen soup. How much of a punch? Well, some species of tick have a bite that can induce a kind of paralysis so brutal, the absence of prompt treatment can be life-threatening. Yes, tick venom, in some cases, can make you go floppier than Charles Krauthammer’s face…and then kill you dead.

The condition is known as “tick paralysis” and is known from more than forty species of tick, from all over the world. Most of the time, tick paralysis is a concern mostly for animals; dogs, cats, and livestock like horses. Fido is far more likely than (most) humans to roll around in ticky areas full of long grass, pick up a shitload of bitey blood bags, and then carry on like nothing is wrong for many days later. Dogs don’t exactly pat themselves down for ticks after a blissful summertime romp in the wilderness, so ticks are more likely to feed for longer in an undetected state.

It’s actually that extended length of time blood-feeding that is crucial in the development of tick paralysis. Symptoms, for unknown reasons, really don’t start until the tick has been gorging itself on blood for at least two or four days. Partially for this reason, in the case of humans, the highest risk group for tick paralysis are young girls, since many of them have longer hair that easily obscure a feeding tick for a long while. Children in general are far more likely to contract tick paralysis (although adults can definitely be stricken down), perhaps partially due to their smaller size (which would make the paralytic toxin more relatively potent), or due to the fact that a squirrelly 8 year-old on a hiking excursion is virtually indistinguishable from the family labradoodle in regards to restraining oneself from barreling into a weedy, off-trail blood-sucker bacchanal.

The paralysis itself is as serious as a stroke, not the least due to the similarity of the some of the symptoms to, you know, the aftermath of an actual fucking stroke. The progression of effects from the paralytic toxin, apparently not released from the tick until at least two days or more into the feeding, start off as subtle. A weak voice here. An unsteady gait there. From there, things tend to get worse by the hour. The legs lose strength and buckle, eventually becoming paralyzed entirely. The paralysis ascends up the body, soon affecting the torso and arms. In a matter of days, a person afflicted by tick paralysis can go from vigorously traipsing through the brush, high on nature, to as limp as an overcooked spaghetti noodle. If the tick is not found and removed, the paralysis may continue to the point where breathing and heart rhythm is compromised. A sufferer with an unaided, frozen diaphragm is, obviously, not long for this world.
Many decades ago, back before more sophisticated public health awareness concerning ticks existed, and back when a much higher percentage of people lived out in rural areas, death by tick paralysis was more common than it is today. There are postmortem reports of ticks being found upon examination deeply embedded into the flesh of folks who had suddenly dropped dead from an unknown paralyzing sickness. The realization that an animal the size of a lentil could slowly and incrementally sicken and kill something as big as a human being must have been difficult to tackle.

Tick paralysis still occurs periodically in the U.S., and luckily, deaths are now very rare (although much more common in pets and livestock). So rare in fact, that when we even consider the hypothetical possibility of endogenously dangerous ticks, we have to turn them into humongous, squealing, alien monstrosities that terrorize a young Seth Green and a freshly-greased Clint Howard in a hilariously shitty 90s sci-fi/body horror flick like an army of murderous haggis:

One of the worst offenders for tick paralysis the world over is found in Australia, because of course it is. Locally, it is known as the “Australian paralysis tick” (or Ixodes holocyclus if you feel like treating this parasite with a modicum of respect and calling it by its true name). This species ranges all along the eastern coastline of the Australian continent and into Tasmania, frequenting dense, humid rainforests that characterize the region. It evolved to target large marsupial mammals as hosts; things like koalas, kangaroos, and bandicoots, but of course, humans and their furriest family members are also adequate substitutes as blood repositories.

During the first half of the 20th century, there were nearly two dozen recorded deaths in Australia from this species, a value that is, by the way, greater than deaths from more expeditiously venomous arachnids like the notorious funnel-web and red-back spiders in the same period. It was this particularly paralytic variety of tick that has inspired the most research into the causative chemical agent behind the venom’s effect, and has yielded the most information. Although, to be frank, we still know relatively little about how this venom works compared to other venomous groups of arachnids like spiders and scorpions. What we do know for certain is that once the tick is removed, the effect of the neurotoxic venom diminishes rapidly, and the paralysis can wane completely within only a day. There doesn’t seem to be much in the way of lasting effects, like you would see in the recovery period after a bite from a venomous snake or spider. You can think of tick venom as a very light, steady drip, introducing neurotoxin continuously, so that as long as the tick is in place and feeding, the paralysis builds over the hours and days. But as soon as the tick is unattached, the body expertly manages to break down whatever toxins were left behind. This is a very different system compared to most potentially fatal neurotoxic envenomations, which tend to rely on one or two injections of a catastrophic dose of venom, followed by the delayed effect on the target’s physiology. Getting bitten by a cobra, for example, is the neurotoxic equivalent of getting hit by a truck. The damage done is nearly instantly dire, and without prompt treatment, death is a near certainty. Tick envenomation is more like getting repeatedly pelted with whole cantaloupes; sure, it only hurts a little at first, but after many hours, the cumulative bruising and bleeding from hundreds of hard-shelled cantaloupe impacts can begin to take their toll. If the onslaught never ceases, then murder by melon is a very likely consequence. Tick envenomation is a regular trickle, not the firehose of single-incident destruction seen in most other venomous animals.

We also know of a small number of putative neurotoxins in tick saliva that may be directly responsible for the paralytic bite. They are known as “holocyclotoxins” and based on both the size of the compounds and the genetic sequence coding for the toxins, they appear to be very closely related to scorpion neurotoxins. There is some thought that these paralytic toxins are a hold-over from before ticks had evolved a parasitic lifestyle from spider-like, non-parasitic ancestors that would have needed potent neurotoxins in their bites to disable prey. Inadvertently killing your meal ticket isn’t exactly a winning strategy in regards to natural selection, so it’s unlikely that it has anything to do with parasitism, and more to do with an evolutionary line that is fundamentally steeped in significantly venomous ancestors.

Ticks’ venom, much like the venom of the hymenopterans I mentioned in Part 1 of this post series (like jack jumper ants and Philippine hornets), is still something that is actively, consciously, and maliciously injected. The hymenopterans have stingers, and the tick has its awl-shaped mouth; both tools that require a fairly direct decision to effectively wield. For example, no one gets stung by a wasp by accidentally bumping into the stinger. The wasp has to actively drive its stinger into a victim. But there are plenty of surprisingly venomous animals that are more passively venomous, allowing bold and naive attackers to make the mistake of doing the envenomation for them, adorning themselves with armor made of hypodermic needles full of biochemical napalm, primed and ready, capable of inducing horrific pain with the slightest pin prick. Stonefish and prickly, venomous caterpillars are among the creatures that come to mind. But there are others, particularly beneath the crashing waves of the tropics, that possess strong (perhaps unexpectedly so) toxins that they can unleash if someone were to unwisely place their hands somewhere they really, really shouldn’t.

Sea urchins are not the most huggable animals in the ocean. Close relatives of sea stars and sea cucumbers (they are all Echinoderms, a term that means “spiny skin”), they are characteristically blanketed in countless hard spines. Urchins exist as little more than a bony globe surrounding huge gonads, a small, but rugged set of teeth, a smattering of gummy tube feet, and a shitload of prickles, plates, and poky bits. Many of these porcupines of the sea tend to do alright against predators by just being tough, unappetizing balls of thorns. But some have incorporated venom right into their spines, and by doing so, become the most regret-filled meals since KFC’s “Double Down Dog”, a culinary abortion so grotesque that I’d tell it to go fuck itself if it didn’t look like it already had.

Oh boy! A post-coital flesh wang and fried chicken labia pairing, with cheese lube included!

Living in Hawai`i, and spending a lot of time in the water around the coral reefs here, I am familiar with a few varieties of these venomous urchins. One of them, the banded sea urchin (Echinothrix calamaris), is a fairly common sight on the reef, their striking white and black ringed spines waggling slowly from their protected position in holes and outcrops. In the Hawaiian language, they are called “wana” (pronounced ‘vah-na’), and are the sole reason I wear protective boots or tabis before I ever wade into the water along a rocky shoreline.

Or why I don’t just reach under rocks or overhangs without checking first.
Photo: Jake Buehler

Wana have a set of spines interspersed with their long, banded ones that are shorter and thinner and far more brittle. These spines easily puncture skin and break off under the slightest amount of pressure, and are finely barbed, allowing them to introduce a flood of venom as they stick stubbornly in you. Last year my girlfriend got to experience the venom of the banded urchin quite literally first-hand, when during a bit of volunteer work leading elementary school children around an exploratory look in the intertidal, she picked up what she thought was one of the harmless species of urchin. It was not a harmless species of urchin. Not even close. The price for her mistake was a quiver of purple to black lances thrust deeply into her finger, making her look like she strayed too close to a mechanical pencil factory during a hurricane.

Ow ow ow ow ow ow ow.jpg
Photo: Christie Wilcox

After pulling out the spines, the intense pain in her finger quickly faded, and the swelling and pain decreased for about a week. But the urchin wasn’t done with her yet, and a few weeks later, pain and stiffness returned to the disfigured phalanx before finally abating for good.

While the hot fire poker pain of a run-of-the-mill venomous urchin spine seems bad, trust me, in the world of venomous urchins, it can get a LOT worse. Far exceeding the potency of the banded sea urchin are the flower urchins, which consist of four species in the genus Toxopneustes. They are found in shallow reef habitats in the tropical and subtropical Indo-Pacific, ranging from East Africa, through the Indo-Australian Archipelago, and throughout the Pacific and across to the coastlines of California and Central and South America. Do not be fooled by the deceptively benign common name. The “flower” moniker refers to the urchin’s numerous flower or cup-shaped “pedicellariae” structures, which are typically small and claw-shaped in other urchins…bear in mind that its scientific name, Toxopneustes means “poison breath”, so that should be a solid indication that it is a dangerous sea beast devoid of warmth or joy. Also, it is those very elegant, delicate-looking “flowers” that administer this urchin’s toxic ruination.

“Eeeeeevery roooooose has its thorn….”

Every suction cup-shaped pedicellaria is equipped with three sharp claws, derived from the grasping appendages more commonly seen in pedicellaria in other urchin species, and looks like some surreal marriage of grappling hook and toilet plunger. Each recurved fang connects to a venom gland. When disturbed, the cup of the pedicellaria snaps shut, like a Venus fly trap, and the fangs overlap with one another, turning the round tip of the pedicellaria closed and more triangle-shaped. The fast and forceful collapse of the pedicellaria tip plunges the three fangs deep into whatever unfortunate fleshy bit (like a human hand, for example) that triggered the reflex. The snapping action automatically opens up a valve in the stem of the claw, and the urchin sends a stream of venom right into the puncture site, like some kind of vindictive, ferocious sea cauliflower.

The most violent of violets, the carnation of carnage, the aster of diasaster…
Daffodil? More like daffo-KILL.

Things tend to go downhill rapidly after that. The claws don’t relax and release on their own, and the stalks for the venomous pedicellaria are brittle, so even a passing brush can not only land you with a dozen “bites” from the world’s most venomous version of those cheap, sticky suction cup ball toys, but the grip of the cups can cause them to break off and stay stubbornly stuck to your skin, where they continue to pump in cascades of burning venom.

This is a pretty goddamn awful situation to be in, because Toxopneustes venom, by urchin standards, really doesn’t fuck around. There appears to be two principal toxin components of the venom nailed down at this point. One of these is peditoxin (comprised of pedoxin and pedin, the former of which, on its own, causes sedation, coma, convulsions, and death in test animals), which, once purified from flower urchin venom, fairly easily kills mice in low doses by inducing a kind of anaphylaxis-like shock. In addition to this, another toxin, contractin A, is known to induce contractions in smooth muscles. It’s not clear how contractin A actually plays out in a whole, living animal (the study used tracheal smooth muscle isolated from a rodent), but it’s important to remember that smooth muscle is found in some fairly important places….like in the walls of major blood vessels, or in the respiratory tract. Having your circulatory or respiratory system seize up, especially while out swimming in the ocean (where a sting is most likely to occur) can be a one-way ticket to Davy Jones’ locker.

And indeed, there are a handful of reports of people drowning after an unfavorable encounter with a Toxopneustes urchin, supposedly caused by the intense flood of envenomation symptoms: the disorientation caused by the electric pain, combined with respiratory distress, muscle weakness, and wide ranging numbness and paralysis, which together overwhelm the water competency of the victim. However, no purported “deaths-by-urchin” have been definitively confirmed. That being said, it’s best not to test this one if out and about on the reef. The peak of flower urchin envenomation effects are apparently short-lived, with the worst pain and paralysis ceasing within the first half hour of the sting, but one must remember that it only takes seconds to minutes to drown…something not exactly helped when the ability to breathe, tread water, and think clearly are shot to shit.

If the harsh sting of the Koosh Ball of Agony wasn’t unexpectedly dangerous enough for a creature that looks more like a dog’s squeaky toy than a real animal, then get a load of the last entry in this post; an animal that appears so benign and motionless that it registers in the brain as more plant or mineral than anything else.

Imagine you’re on the vacation of a lifetime, SCUBA diving off the equatorial coasts of Indonesia’s island of Sulawesi. You are some forty feet below the surface, surrounded by the serenity of some of the richest and most diverse coral reefs in the world, the only sound your rhythmic breathing and the rush of bubbles from your regulator. Towering coral pinnacles flank your gliding path along the reef, great, complex, stony structures of purple, yellow, and navy blue. Clouds of minuscule, neon green damselfish undulate and contort around their stationary place above a coral head as you approach. The water is a warm 82 degrees, and isn’t much cooler below the surface, so you are only wearing a short-sleeved wetsuit. You catch a glimpse of something big, fast, and deep blue blazing off to your right. It’s a humphead parrotfish. You signal to your dive buddy and follow cautiously, watching it slow down and maneuver around a field of broad, olive-yellow, branching corals. It disappears through a hole, but you know it has popped out the other side. You know you need to rise up above the wall of branching corals in front of you, so you ascend slightly, attempting to peek over the edge. You can hear the parrotfish feeding just on the other side, so you need to move as slowly as possible, so you don’t scare it away. You ready your camera, and reach out to steady yourself by grabbing onto one of the thicker regions of the weird, smooth, lacey coral in front of you. You stop, remembering that Kent, the divemaster, had specifically directed you and your buddy to not touch any wildlife if possible…ESPECIALLY not the sensitive corals. Kent is a 42 year-old white man with dreadlocks, a DMB logo arm tattoo, who talks incessantly about his recent “juice cleanse” and the “spiritual awakening” he had volunteering and (inadequately) constructing school houses in Uganda. Fuck Kent, you think to yourself, and firmly grab onto the coral with your bare left hand and pull your weightless body upwards.  You snap some amazing photos of your parrotfish subject, and continue on your way, finishing up your dive shortly. As you ascend with your dive group to the boat, you notice a burning sensation in your left hand. You shake it out a bit and stretch your fingers back and forth. The pain gets worse, and by the time you flop back onto the boat, the stinging radiates through your entire palm. This is just the beginning of a week-long ordeal of pain, irritation, and suffering.

On your dive you unknowingly made a grave error; touching fire coral (Millepora), incurring its venomous wrath straight into your soft, unprotected hand.

The term “fire coral” is actually misleading. The fifty or so species of Millepora, found across the Indo-Pacific (except for Hawai`i) and the tropical Atlantic and Caribbean, are not corals at all, and are actually quite distantly related to them. While both “fire coral” and standard stony corals are colonial animals in the phylum Cnidaria (a group that also contains jellies and sea anemones), they are in entirely different taxonomic classes. True stony corals are what we call “anthozoans” (a term meaning ‘flower animals’), and are close relatives of things like anemones and sea pens. “Fire coral”, in contrast, is a “hydrozoan”, and is closely related to things like freshwater hydras, colonial siphonophores like the Portuguese Man ‘o War, and the by-the-wind sailorMillepora is a member of a group of cnidarians that includes creatures that look and act a lot like “true” jellies, class Scyphozoa (“jellyfish” or “jelly” is a term that is applied to many groups of free-swimming, bell-shaped cnidarians, whatever their evolutionary lineage)….yet, to the untrained eye, looks indistinguishable from any of the corals that make up the reef.

However, looking closer at these vast colonies of hydrozoans helps illustrate just how different they are.

Both Millepora and true stony corals are colonial organisms, meaning that their big, branching structures are made up of many multitudes of single organisms (called “polyps”), articulated and fused together like the apartments making up a high-rise skyscraper. Coral polyps are like very, very tiny sea anemones in overall shape; little mounds with soft tentacles surrounding a mouth hole. They are, however, encased in a hard aragonite skeleton (a “corallite”), with the feeding tentacles (which are covered in “cnidocytes”, the explosive, venomous harpoon-primed stinging cells found in all cnidarian groups) alternating between being exposed to the water, or retracted within the skeleton. Corals feed on planktonic bits that stray into their outstretched tentacles, and most shallow water species are also supplemented by symbiotic unicellular algae (“zooxanthellae”) that live inside of the polyps and provide food energy via their own photosynthesis.
Millepora also harbor zooxanthellae and derive energy from them, but the structural units by which they generate their giant colonies are markedly different. Instead of distinct polyps sheathed in a rigid corallite, the surface of a fire coral colony looks like close-up of Edward James Olmos’s face. It is a plain of diminutive pores and pockmarks (“millepora” means “thousand pores”), each housing a polyp. However, in fire coral, the polyps fall into a number of different types. The two most common types are gastrozoids and dactylozoids. Gastrozoids are the feeding polyps, and in this way, are similar to what you’d see in a coral polyp. Most of the time, gastrozoids are retracted deep below the surface of the colonial skeleton, where they are connected to one another by a network of canals, so nutrients can be distributed between individuals. The dactylozoids are strange by comparison; mouthless, their job is to catch prey and feed it to the gastrozoids. They have long, thin, wispy, transparent tentacles that stick straight out, making the colony look like it stole its hair style directly from Bernie Sanders. These dactylozoids and their tentacles are the ones armed with the stinging cells that dole out the pain to microscopic plankton and misplaced human limbs alike.

Feel the Bern….literally

Contact with the dactylozoid tentacles causes the cnidocytes to do their one and only job; shoot out a barbed harpoon at blistering, impossible speeds directly into whatever triggered it. How impossible? The discharge of the stinging cells takes roughly 700 nanoseconds, which is an acceleration so stupidly huge that the harpoon is subjected to more than five million times the force of gravity….some 5,410,000 g. This mechanism produces, far and away, the highest acceleration of any animal on the planet. To put that value in perspective, for a human to experience that g-force on a standard merry-go-round with a 15 meter radius, you would have to be spinning around at more than 182,000,000 miles per hour. This is so fast that you would travel the equivalent of the Earth’s circumference in less than half a second. Not only would the force nearly instantly liquefy you, even down to the collagen that holds your tissues together…but the air friction generated from such speeds would incinerate whatever remained.

Basically, what I’m trying to say is that the spring-loaded harpoon of a discharging cnidocyst is fast.

Once that harpoon tip hits its target, venom is injected into the puncture site through the hollow tubule that runs from inside of the harpoon, down the thread, and into the capsule of the cnidocyte. Cnidarian stings vary widely in how seriously they impact human physiology. Many sea anemones have mildly irritating stings, while some cubozoans (box jellies), like the sea wasp (Chironex fleckeri) has sting that has been implicated in human fatalities. Fire coral falls somewhere in the middle. For Millepora, it takes usually at least a few minutes for the first symptoms to show up after a sting. Hot, burning pain is the predominant shit you would have to deal with, and it is the first to rear its head. Red, irritated welts and blisters raise on the skin in the impacted area, and in some cases, in the hours following the sting, the sufferer may experience nausea so strongly they end up barfing a bit. The pain eventually gives way to intense itching after a while, and the red rash can remain for a week or more. The sting’s effects are certainly unpleasant, a little like mosquito bites on top of poison ivy on top of a gnarly sunburn, but they are, at least, not life-threatening. Barring a rare allergic reaction, fire coral ain’t going to kill you. Really, a much more likely scenario to be cause for concern is if someone came in contact with Millepora by getting scratched or cut by it. Cuts sustained from coral or Millepora are exposed to mucus from the coral, full of irritating proteins, as well as tiny chunks of calcified skeleton. This, together with the cut being submerged in a marine soup of microorganisms, means that coral scrapes are particularly slow to heal and infection-prone. If the skin is broken, essentially, the most dangerous element of a fire coral encounter potentially has nothing to do with the venomous colonial critter itself.

So, it’s just good policy to not touch anything that looks like it could be coral. Touching pisses the coral off and/or kills it, and touching coral can end up indirectly hurting you, and THAT pisses YOU off. There’s not a lot of winning here.
Don’t touch urchins, either. Even if they look like they are made entirely out of gelatin trumpets. Actually, especially if they look like that.

Venom has evolved in a hell of a lot more critters than snakes, scorpions, and spiders. Some of them are brightly-colored buzzing nightmares, some are underestimated miniature vampires, and some don’t even look like animals at all. Takeaway from all of this? If you are out in our big world and see a new beastie thing, and you desperately want to pet the thing, remember that maybe you really shouldn’t pet the thing.

Image credits: Intro flower urchin, tick hypostome, tick before and after feeding, Toxopneustes, flower urchin pedicellaria, fire coral scene (Derek Keats), fire coral tentacles (Eric Burgers)

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Venomous and Underrated: Hymenopteran Horrors

I have a penchant for particularly noxious lifeforms, the ones that have evolved nasty chemical tools for either fending off bigger, badder, and hungrier things, or bringing down breakfast. Anyone who has read the breadth of this blog should now be aware of my adoration of the biology of such fundamentally antagonistic critters, the mark of which has been left behind in the number of entries devoted to the lesser-appreciated toxic flora and fauna of the world. Deadly, toxic mushrooms. Boxfish, with their poisonous mucus. The terrifying, seafood-driven, hallucinatory rollercoaster ride of ichthyoalleinotoxism. Pungent vinegaroons and acrid harvestmen. Venomous caterpillars that make you bruise like a peach….to death. Birds that silently embed concentrated toxins in their fucking feathers.The “Do Not Touch” exhibit in the Museum of Life has made a strong showing within the overall theme of Shit You Didn’t Know About Biology. I mean, Christ, my very first post on here was about an insatiable aphid-slaughtering deathdozer that bleeds poison foam.

Most of the unsavory representatives above are of a particular variety of being, well, molecularly disagreeable. Up until now, I’ve chiefly yammered on about “poisonous” and “toxic” organisms (with the exception of that intimidatingly venomous caterpillar), things that secrete or store harmful compounds in or on their bodies, such that the aggressor the poisons are intended for must passively absorb the toxins through digestion, or through the skin and mucus membranes (considering my research on boxfish, this bias towards this type of defensive strategy shouldn’t be all that surprising). Nature also hosts plenty of “venomous” organisms, which entails a much more direct, Type A approach to chemical warfare, wherein the poison punch is forcefully injected via a (generally quite pokey) delivery system that has evolved specifically to fuck up your day.

There are plenty of well-known venomous superstars, and it is especially the venomous snakes and spiders that garner the lion’s share of the limelight. A fair number of people are familiar with the superlatively deadly representatives of these groups, from sea snakes, cobras, and taipans, to Brazilian wandering spiders and Sydney funnel-webs, which regularly make appearances on just about every heavy-handed, suspense-saturated, kitschy “TOP TEN DEADLIEST” daytime special to run on Discovery, Animal Planet, or Nat Geo for the last decade or so.

But the brush painted by the evolutionary strategy of venom is broad, and the technique has cropped up in a surprising number of very distantly related lineages. This two-part series of posts will be devoted to the unsung venomous animals, which neither slither through the grass or canopy (nor thwart the professional efforts of John Goodman), and within their ranks, not even necessarily the most dramatically dangerous or traditionally telegenic and charismatic representatives. These other animals, however, have evolved injectable weaponry that is truly remarkable on its own merits, by a diversity of metrics, despite not achieving comparably towering levels of renown. Much attention has been bestowed upon the black mambas and black widows, the Clooneys and Jolies of venom notoriety. It’s appropriate to give the Goldblums and Leguizamos their day in the sun for once.

When it comes to animal diversity, insects are an undisputed juggernaut. Their taxonomic class, Insecta, potentially holds as many as ten million species…but it’s a quantity we can never quite pin down, since we continue to discover truckloads of never-before-seen creepy-crawlies just about every goddamn time we peak into the dark, dank undergrowth of equatorial rainforests, so our admitted level of ignorance tends to be a moving, inflating entity.

But there is one insect group within this overwhelming ocean of species, more than any other, that has forced humans to have an intimate familiarity with the throbbing cruelty of venom. This group numbers 150,000 species strong or more, and is found on essentially every major landmass on the planet. Entomologists know them as the Order Hymenoptera. To most everyone else, they are the bees, wasps, hornets, and ants. Hymenopterans, as a group, are responsible for more annual human deaths then just about any other venomous clade. In the U.S. alone, about 40 to 50 people die from just bee stings every year. Part of this is explained the by the allergenic properties of hymenopteran venom, and how severe allergies to stings aren’t all that uncommon. The other reason is tied to contact; the angry, swarming, stinging bastards are everywhere. Large numbers of humans have had heated interactions with hymenopterans at some point in their lives. Whether it was stumbling over a yellowjacket nest, or getting a little too close to that arboreal, roadside beehive, the transgression invites a cloud of livid, buzzing pain-missiles upon their panicked, flailing selves. The burning of potentially dozens of stinger-fulls of venom is an experience billions of humans learn to carefully avoid.

Personally, I regard hymenopterans with a severe level of caution; not because of an allergy to their stings, but because of my near-phobic degree of fear in their presence (a feeling of unrelenting trepidation that also has driven a fascination and respect for their incredible biology). But even I had to learn their venomous nature from early, first-hand encounters. My earliest interaction with a bee occurred when I was three years old, playing in my grandmother’s landscaped front yard. I was convinced that the silly, fuzzy, striped bug sniffing all the flowers would feel nice and soft in my pudgy toddler hands.

It did not feel nice. It did not feel nice at all.
I haven’t felt comfortable around bees since. First impressions fucking matter.

Beyond your common honeybee or picnic-crashing ant, there are a number of famed members of the hymenoptera long recognized for their especially brutal stings. These Celebrities of the Sting are worth mentioning briefly, if for nothing else but to get their prestigiously painful asses out of the way. For one, the fire ant (Solenopsis invicta), native to tropical South America, has a well-earned reputation for aggressively defending its colony by vigorously stabbing trespassers with a decidedly painful venom, resulting in the eruption of searing blisters and, potentially, anaphylactic shock. Fire ants have commanded worldwide attention due to their status as a hard-to-eradicate nuisance and invasive species in the Southern U.S., parts of East Asia, the Caribbean, and Australia (a place that certainly doesn’t need more cantankerous beasties). Then there’s the fire ant’s notorious cousin, the bullet ant (Paraponera clavata), also native to the Neotropics. This gargantuan black ant, burly enough to hug a penny, is thankfully not established anywhere outside of the deepest recesses of Central and South American rainforests, because it harbors a sting widely regarded as the most painful on the planet. That name? Bullet ant? It has nothing to do with its 400 m dash time or its NRA membership. No, it’s called the “bullet ant” because its sting makes you feel as though you’ve been fucking shot with a handgun. You then endure the wonderful experience of unabating, unfathomable quantities of madness-inducing agony, making you sweat and tremble uncontrollably for what seems like an eternity of supernaturally savage punishment.

If you’ve ever sat through the 91-minute runtime of this cinematic abortion, you’ll know the feeling

But lastly, buzzing ominously above the zenith of hymenopteran sting infamy is the Asian giant hornet (Vespa mandarinia), very recently made familiar to the world outside of its native East Asia thanks to nature programming and the collective gasping and shivering of a generally entomophobic Internet. I’m not entirely certain why, seeing as how it’s fundamentally no different than a normal hornet….except for how it’s bigger than a canary, has a quarter-inch long stinger, and is consequently the most distilled, pure incarnation of “hell fucking no” to ever exist. And how they spend their time nonchalantly pinning down things more than twice their size and chewing off their faces. And how they violently dismember European honeybees faster than Spartans mowing through Persians in a Zack Snyder film. And how they do things like this to the most fearsome, heartless insect predators around:

Yes, it’s eating a praying mantis. And yes, you just peed a little.

Oh, and then there’s that whole thing about how when it plunges that jumbo-sized stinger, which is as thick as a motherfucking thumb tack, into your delicate, mortal flesh, it feels like “a hot nail” being driven through you. It’s less “bee sting” and more “getting stabbed with a soldering iron.” The volume of venom unloaded by these stings is likely three times higher than what more modestly-sized hornets dole out, and because of this, a comparably low number of stings can be life-threatening, even for the non-allergic. Seriously, particularly bad attacks of Asian giant hornets end up killing people by the dozen on the reg, immense volumes of venom turning their organ systems to jelly.

So, yes, perhaps no hymenopteran is as viscerally manhood-wilting as Vespa mandarinia, but in actuality, the world’s largest hornet only holds a title in regards to its girth. Part of the reason so many people are killed and injured (as many as 1,600 in what probably seemed like an astoundingly apocalypse-y year for northern China), is because this hornet is common in low elevation forested habitat near some of the densest aggregations of humans on the planet; Japan and coastal China. This means that humans and giant hornets are relatively likely to run into one another. Despite its overall lethality and destructiveness to human happiness, this yellow-and-black, colon-purging nightmare isn’t especially venomous as far as hymenopterans go.

To find the possessor of the most potently pernicious posterior prick among wasps, one must go to the Philippines and hunt down the Asian giant hornet’s relative, Vespa luctuosa. This hornet, endemic to the Philippine archipelago alone, doesn’t have a common name, which opens the door to me coming up with one on my own for the sake of ease. The Philippine fucker-upper. The Manila killa’. The Pinatubo painmaster. But perhaps simply “Philippine hornet” will work better here. In life, the Philippine hornet doesn’t really stand out from the hornet pack. It lives a standard, tropical hornet life, crafting spherical papier mache nests that hang from rainforest trees like the world’s least enjoyable piñata. It has a notably darker coloration than many hornets, with only a few thin, rogue bands of deep yellow appearing at the back of the abdomen near the stinger.

Yeah, dark…like its soul
Photo: Lary Reeves

Additionally, the Philippine hornet is something of a hermit, generally not associating well with human encroachment and keeping to itself in undeveloped regions of the hot, humid rainforests it calls home. This is definitely for the best, since this drab hornet has a venom whose potency ranks highest among wasps, and is one of the most potent of any insect, period.

Toxicity of substances is often given as an LD50 value (or a “median lethal dose”), which represents the dosage of venom needed to, statistically, kill 50% of a given population of a test animal. Often, this dosage is listed as milligrams of venom per kilograms of mass of the poor, envenomated subject sacrificed on the lab bench (often a mouse). The value also tends to vary with how the venom is injected (below the skin vs right into vein, for example). The lower the LD50, the higher the toxicity, since a lower concentration is needed to achieve a 50% kill rate. The Philippine wasp’s venom has an LD50 of about 1.6 mg/kg in mice, and in contrast, the imposing Asian giant hornet has venom achieving a value of over 4 mg/kg. Compared to the most venomous snakes, like Pseudonaja and taipans, this is 10 to 100 times less potent. Philippine hornet venom is more on par with that of the king cobra (Ophiophagus hannah) in drop-for-drop deadliness. If the idea of hornets flying around with honest-to-Jiminy-cocksucking-Christ cobra venom in their stingers makes you sweat like Ned Flanders in a strip club, consider that envenomation volume makes a huge difference. The king cobra can pump out as much as seven milliliters (a quarter of a whiskey shot glass) of venom in a single bite, but the sting from a single Philippine hornet is going to dispense a tiny fraction of that amount. However, this venom is potent enough that each hornet possesses enough venom to statistically kill a dozen mice; meaning, that if you took their entire load of venom, and distributed it among twenty-five mice, statistically, half of them would die. That’s not “cobra serious”, considering that hornets don’t blow their whole venom load in a single sting, but it’s conceivable to see how an uncoordinated trailblazing effort, a clumsy collision with a colony, and dozens of stings later might put your ass in some hot water, sting allergies not even considered.

This one has a pin sticking through it, and is a dried-out, four decade-old corpse, which makes it slightly less dangerous than normal.

“Well,” you say, sitting in the air-conditioned comfort of your home in the Tempe ‘burbs, “it’s a good thing I don’t live in the Philippines.” Sure, you think, living in Arizona, Earth’s scrotum-melting broiling pan, has its own throng of difficult residents that goes along with it. Rattlesnakes. Scorpions. Gila monsters. Homophobes. Racists. Racists. Still more racists. Racists everywhere. Did I mention racists? But you can adjust to all of that in time, and through simple things like developing a drinking habit and never going outside during the daytime. It’s not like the most venomous insect on the planet could potentially skitter up to my sun-scorched doorstep or something.

Oh yeah, except for how that’s totally a thing that can happen.

North, Central, and South America are home to a genus of ants (Pogonomyrmex) collectively known as “harvester ants.” They are a diverse group, and about seventy species of Pogonomyrmex run frenetically across the hot, arid regions of the New World. They, much like the aging Tucson hippies they share their habitat with, are seed-eating specialists, and workers forage for small seeds to take back to their subterranean nests. They are industrious little creatures, and as a result, there tends not to be much in the way of vegetation growing near the entrances to their colonies, the landscaping dominated by sand and gravel. Outwardly, they are unremarkable as far as ants go. Small. Bent antennae. Six legs. Pinched waists. Bullet-shaped butt and a round head. Chastises Grasshopper for being an ever-idle moocher. No surprises here.

That is the most anty-looking ant I’ve ever seen.

Look a little closer though, at the far right, at the teardrop tip of its shiny, caramel abdomen. See that sliver poking out through the white bristles there? That is a stinger, not unlike that of the Philippine hornet or any other typical hymenopteran.

It’s important to remember that while ants are a big group, with a towering number of species in their ranks (somewhere between 12,000 and 20,000+, it’s hard to tell), they all reside within a single taxonomic family (Formicidae). A family, by the way, nestled among a whole suite of families of “wasps” in a superfamily cluster termed the “vespoids” (which are all your typical, yellowjackety, waspy type creatures). Ants are just a group of specialized vespoid wasps that have taken to the ground and lost their wings. Well, most of them. Many species reserve the retention of wings for a select few social castes. Ants are newcomers among insects, diverging from their wasp brethren only within the last 120 million years or so, and it’s easiest to think of the family as simply wasps with a few modifications. Certain features of their biology and anatomy betray their ancestry, and more so in more primitive groups of ants. For example, a powerful, painful sting tends to associate with groups of ants that were earlier offshoots within the family; the notorious bullet ant, with the most brutal sting of all, is a member of a comparatively ancient group of ants known as poneromorphs. In the “canopy” of the ant family tree reside lineages that have lost stings altogether, converting their venomous butt darts into a contraption that sprays formic acid.

Pogonomyrmex is one of those ants that holds onto the weaponry of its aerial forebears with as much tradition-rescuing, white knuckled zeal as an 80 year-old defiantly maintaining that the restaurant down the street serves “Oriental” food. And boy, have they found a way to make it their evolutionary nostalgia count. Harvester ants, as a group, have the most venomous stings of any insect, with the highest honor falling upon Pogonomyrmex maricopa, a nondescript ant found chiefly in the Sonoran and Chihuahuan Desert regions of Arizona, but actually ranges through the adjacent desert lands of Utah, Nevada, southern California, and New Mexico. This species has the most potent venom of any insect, with an LD50 recorded at 0.12 mg/kg. For context, consider that this is more than ten times more potent than the already hyper-venomous Philippine hornet’s sting, and has a similar punch to the venom of the Russell’s viper (Daboia russelii), a snake infamous for killing thousands of people across South Asia every year. From the human perspective, these guys are itty bitty, and each sting delivers a minuscule dosage of venom. But it does the job, and the result is several hours of hot, blinding pain, effectively making Pogonomyrmex maricopa‘s sting the most aggressively repellent thing to hit the Grand Canyon State since Joe Arpaio flew on in, powered solely by jowl oscillations and hot air.

But why have such a dickishly venomous sting? Not all ants, apparently, have the need to be so outlandishly nasty, so why the harvester ants? The answer lies in how venoms evolved in hymenopterans. Hymenopteran stingers evolved from the egg-laying tubes (called an “ovipositor”) of females to dispense a painful, toxic chemical “persuader” to unwise attackers of a colony or nest. The entire point of these venoms is to induce enough torment that a nest raider loses all motivation to complete Operation Tear Open the Humming Food Ball, and instead limps off to engage in Mission Lick Wounds and Whimper Self to Sleep. It also helps if the experience is agonizing enough to keep the intruder from returning without a careful evaluation of its life choices. The sting of a hornet or an ant is there for defending the hive or nest, often from something big and hungry. So what the hell are the harvester ants defending themselves against that would necessitate the evolution of such potency?

Enter the Texas horned lizard (Phrynosoma cornutum), a thorny, squat, tank-like lizard that makes the arid lands of the interior Southwest its home. Biologists know it as a member of the diverse group of “North American spiny lizards” that are found all over the continent, but you may know it as that one lizard that can turn its blinkers into a blood cannon or as the star of the “Laughing Lizard” Internet meme. The Texas horned lizard may look a little comical; it’s hard to take seriously an animal that looks like a combination of a frog and a cactus that was run over by truck. But when it comes to eatin’, this lizard doesn’t fuck around. The Texas horned lizard, fitting right in with the Lone Star State crowd, has a heightened culinary appreciation for spicy food, as more than two-thirds of its diet consists purely of Pogonomyrmex ants. This is an animal that trains its blank, saurian gaze on a pulsating, angry, red mound of toxic fury and says “yeah, I can eat that.” The horned lizards, as a group, are harvester ant-eating specialists. I really mean “harvester ant specialists” too. They target these picante pricklers only, and will forgo eating things like invasive fire ants, which is actually the less venomous, “pico de gallo” alternative, and rigidly stick to their native, “ghost pepper” option. This is actually a conservation problem for horned lizards, because invasive, omnivorous fire ants are currently killing and eating harvester ants at a breakneck pace…eliminating the bulk of the horned lizard’s diet, leading to falling lizard populations.

There’s evidence to suggest that the super-charged stings of harvester ants are the result of such aggressive, narrowly focused predation, resulting in a coevolutionary feedback loop, where the ants evolve even stronger stings, and in response, the horned lizards come back them with the evolution of even better venom tolerance. It turns out that horned lizards are really goddamn good at absorbing Pogonomyrmex stings. How good? Better than mice, that’s for sure; the LD50 for Pogonomyrmex maricopa venom in horned lizards is 162 mg/kg. This means that it takes more than 1,300 times more venom to, statistically, kill as many horned lizards as it does mice of the same size. The difference in venom tolerance between horned lizards and close relatives is huge as well, just in case you thought it a reptile-vs-mammal thing was to blame; the LD50 for the venom in the fence lizard Sceloporus is a sixth of what it is in Phrynosoma cornutum. The resistance appears to be something running through the lizards’ inner piping, because when you inject mice with horned lizard blood plasma, the some of that resistance to the ant venom is transferred over. Horned lizard physiology casually shrugs off harvester ant venom proteins, handily detoxifying the deadly cocktail like it was nothing more than baby aspirin.

Horned lizards also avoid getting too much venom into their bodies in the first place by incapacitating the ants. However, this happens much later in the “eating chronology” than most people would prefer for consuming an army of six-legged hellfire. Horned lizards rapidly gobble down the ants whole, attempting to eat dozens in a single sitting. When the wee bastards enter the digestive system, they are very alive and more than a little piqued. Before they can arch their abdomen back and unleash a bout of heartburn that reptile won’t soon forget, they are enveloped in thick, heavy mucus, and frozen in place as they are shuttled down into the stomach. Horned lizards have evolved a series of unique, finger-like projections and folds that line the inside of their upper digestive tract and produce copious amounts of snot that binds and immobilizes the ants as soon as they get swallowed. Horned lizard gullets are like a water slide, but pitch black and full of molasses. They can shovel ants in their mouth freely, never worrying about hymenopteran havoc being wrought on their vulnerable stomachs. I guess you can say all that protective phlegm acts as an….ant-acid.

See? He thinks it’s funny.

The combination of this, and how they brush off harvester ant venom like Bukowski brushing off half a handle of bourbon, allows horned lizards to fill up on the most painful meal in the desert in relative peace, unaware of the silent, coevolutionary war taking place between them and their food for hundreds of millennia.

You may have noticed that the correlation between venom potency and danger to humans isn’t very strong when it comes to these insects and their stings; Asian giant hornets kill heaps of people annually, but have relatively mild venom, and the chemically formidable stings of Philippine hornets and harvester ants may hurt like shit, but haven’t really been associated with human fatalities. Are there any ants, then, that somehow manage to summon EMS sirens wherever they clash with humans, despite their relatively dinky potency?

The answer is yes, and they can be found in Australia. Because of course they fucking can.

Australia is no stranger to periodically murderous wildlife, especially of the venomous variety. Hell, half the examples of highly-venomous snakes and spiders I’ve mentioned in this blog post hail from Oz. The entire goddamn island continent is awash in a diversity of venomous animals, a disturbingly high proportion of which are armed with venom vicious enough to drop your carcass to the hot, antipodean dust for one of those “forever” kind of naps. I’m half convinced that koalas and wombats aren’t real animals, and were artificially contrived by the Australian government to distract tourists from the ever-present, shin-deep layer of funnel-web spiders blanketing the country. I suspect Australia is so damn dry because rain is simply too afraid to fall there. What I’m trying to say is that Australia is what’s on the other side of the inter-dimensional, fog-bound portal in The Mist.

So, it is no real surprise that something as cartoonishly intimidating as the bull ant (Myrmecia) feels comfortable enough to make its home there.

That right there is about two centimeters of NOPE

They are an old, primordial group of ants, with essentially no close living relatives. Their primitiveness is readily observable in their social structure and the loose delineations between castes. They aren’t nearly as cohesively cooperative with one another as more recent ant groups. There’s more of a libertine, laissez-faire approach to things, with more infighting, and less collectivist, colony-driven, group motivations. The division of labor isn’t as well-pronounced, nor is the presence of physical differences between reproductive and worker castes. For example, they are among the few lineages of ants that, in addition to a queen, possess “gamergates” in their colonies; worker females that retain the ability to mate with a male and reproduce. The fossil record shows that back in the Cretaceous, bull ants had a large geographic range, extending onto just about every continent. But, in the modern age, the remaining hundred species of ant in the genus Myrmecia are all found only upon the continent of Australia (save for a single species holding out on New Caledonia, a nearby group of islands between Fiji and the Solomon Islands). Apparently, this is an ant that liked to live dangerously, and after the dinosaurs went worm counting, the only place left that was treacherous enough to set up shop and keep the adrenaline pumping was fucking Australia.

An encounter with Myrmecia in the flesh truly does engender the feeling that they hail directly from a bygone prehistoric age, full of harsh challenges that the lily-livered ants of today could never even imagine. For one, the worker ants are gigantic by ant standards. While not the largest ants in the world (surpassed by the famous, previously mentioned bullet ant, and the tocandira), many bull ant species can have a worker caste that can nearly reach an inch and a half in length, which is longer than the distance between the tip and first knuckle of your thumb….not that you’d ever want to get your hand close enough to measure. Secondly, you may have noticed that bull ants have a set of weaponry that most ants do not; serrated, pinching jaws, longer than the head, extending forward like a pair of cruel bread knives. These mandibles aren’t just for show, and can snap together with blinding speed and savage force, puncturing and clenching whatever is in their path. Bull ants have pneumatic meat hooks where their face should be.

Aww, look! She’s smiling!

Evolution has molded these ant mouthparts (which are normally quite modest in other genera of ants) into Satan’s pinking shears, and they have a key job in the life of the bull ant. And while I know they are intimidating to look at, no, it isn’t killing and dismembering buffalo. The adult ants are omnivores, eating everything from nectar, to fruit, to seeds, to the liquefied remains of small insects…but their maggot-like young are fully carnivorous, and require a fresh, dripping kill to grow up big and strong. So, adult bull ants lead an active and athletic foraging lifestyle, usually solo, using their big eyes and keen eyesight to track down prey from surprisingly long distances away. Bull ant workers then use those brutal chompers to pin down anything they can in a vice grip; grasshoppers, beetles, more pusillanimous species of ants, and, in a bizarre table turn of food web convention, spiders. Yes, spiders. Charlotte’s Web would have ended slightly differently were it set in Australia.

“Wilbur! Wilbur, help! Wil-ggaaaaghhh!!!”

But the killing blow to their wriggling, soon-to-be-baby-food quarry comes from Myrmecia‘s venomous sting. And it is their sting, not their bite, that makes bull ants dangerous to humans. In fact, one small, common species, Myrmecia pilosula, the “jack jumper”, so named for its habit of lunging and bouncing when disturbed (a similar behavior is seen in Myrmecia gulosa, the “hoppy joe”), is responsible for several human deaths, and is the cause of many hospitalizations in Eastern Australia and Tasmania. Bull ants like the jack jumper and hoppy joe may have disarmingly ridiculous, very Australian nicknames that sound more like a brand of small firecrackers and a rabbit-themed coffee shop, but it is clear that their venom is nothing to giggle at.

The jack jumper is an ant that shies away from the dense urban habitats of Australian population centers like Melbourne, Brisbane, and Sydney, but is common in open, more undeveloped areas all over the country. They easily stake their claim and establish colonies on the borders of suburbia and rural regions, and as a result, humans regularly spot them and are stung by them when engaging in outdoor activities. This is a problem, because the venom from these ants is apt to kill people dead.

The deadly nature of Myrmecia venom isn’t related to a blanket potency. Realistically, bull ant stings generally aren’t particularly venomous, on their own, compared to other hymenopterans. Much of the time, a jack jumper sting results in a painful boil and local swelling that persists for a few days, similar to a fire ant sting. Not much is known about the venom’s calculated potency in whole animals, but pilosulin 1, a protein in jack jumper venom, is known to have an LD50 concentration value for a certain type of white blood cell that is four times lower than melittin (a major component of bee venom).

However, it isn’t the straight toxicity of compounds like pilosulin 1 that make a jack jumper sting potentially deadly, it’s the uniquely allergenic properties of the venom. Jack jumper stings are dangerous because a shitload of people have severe allergic reactions to them. In Tasmania, where jack jumpers are highly abundant and cause the majority of severe stings (and resulting deaths), the prevalence of severe allergies to stings sits at around 3%, twice as high for honeybees (a hymenopteran famous for getting the immune systems of countless humans to self-destruct with deadly consequences). Unsurprisingly, the same study linked to above has shown that as many as one in fifty Australians have reported anaphylactic reactions to stings from jack jumpers or other Myrmecia ants. In Australia, most anaphylaxia cases from insect stings are attributed to jack jumper ants, not from bees, making Australia possibly the only place in the world where bees are beaten at their own immunogenic game.

Not only are jack jumper stings more likely than bees to send you to the hospital, a pale, swollen, barely breathing mess a step away from death…but they are more likely to do it more than once. If you’ve had a major allergic reaction to a jack jumper sting, and you get stung once again, you might not want to wait until the symptoms get bad before you get the fuck to the hospital. There’s a 70% chance that this repeat sting will initiate a catastrophic allergic reaction just like the last time. For honeybees? It’s about 50-50. About half as likely than that for wasps. Myrmecia stings do what honeybee stings do, but they do them better. Better than an animal that, generally speaking, is really damn likely to kill you…more likely to kill you than pretty much any other.

This potent allergenic effect probably isn’t mitigated at all by another protein in jack jumper venom; pilosulin 5. Pilosulin 5 causes mammalian mast cells to dump buckets of histamine all over the place…you know, the same crap that basically causes all symptoms of every allergy ever.

The jack jumper issue has been so bad for so long in Tasmania, that around a decade ago, an immunotherapy program was set up to desensitize the particularly allergic to the venom. It has been largely successful, and it, along with enhanced public awareness of the dangers of the venom, has contributed to a sharp decline in jack jumper sting deaths in the island state. Until the start of the new millennium, someone perished at the butt-end of a jack jumper once every few years, but there hasn’t been a recorded death that can be attributed to the ant for more than a decade now.

Hymenopterans and their venom manage to reign supreme in the insect world, but underappreciated venomous critters abound in many lineages and environments. To see some, you may have to plunge into tropical, coral reef waters, and for others, just go for an off-trail jaunt on your next backwoods hike…. (continued)

Image credits: Intro image, giant Asian hornet eating mantis, pinned Vespa luctuosaharvester ant, Myrmecia and ruler, jack jumper close-up, Myrmecia catching spider

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

High Tide: Hallucinogenic Fish

I love to eat fish.

Fish is by-and-large my favorite dietary source of protein, and living in Hawai`i means that I get to indulge in this adoration for finned flesh perhaps more often than I should. In the islands, there are plentiful, fresh fish of a staggering diversity sold and consumed everywhere you turn; firm and buttery a`u (Pacific blue marlin, Makaira nigricans), rich opah (Lampris regius), ubiquitous mahimahi (Coryphaena hippurus) and `ahi (Thunnus), lean and flaky ono (Acanthocybium solandri), and delicate `opakapaka (Pristipomoides filamentosus) are just a few. There’s also uhu, ulua, aku, uku, mamo, manini, akule, palani, awa, ama`ama, u`u, opelu, nenue, kamanu, omaka, hapu`u, `ula`ula koa`e, moi, ukikiki, kahala, kala, umaumalei, wahanui, and moano too. Introduced species? Hawai`i has roi, ta`ape, and to`au. Great, glistening troughs of poke line the deli section of just about every grocery outlet on my island (Safeway, local chains….liquor stores), and upon seeing them, I inevitably have to command my legs to carry me away from a fate involving a plastic container of heaven, chopsticks, and a wallet seven dollars lighter.

There are a number of reasons why avoiding the reduced price special on the limu `ahi at the Liliha Foodland may be a wise decision for just about anyone (temporarily salvaged funds unconsidered). As with any food, there are inherent risks, and fish have a unique repertoire of ways they can make a regretful meal. Perhaps the most readily publicized is the health risk posed by the bioaccumulation of methylmercury in the tissues of a number of fish species typically taken as food by humans. One bite of a particularly metal-saturated swordfish steak isn’t going to promptly send you to tea with Alice and a rabbit, and the accumulation of the poison in humans takes time (and LOTS of contaminated fish consumption). But, there are more acute ways a fish filet can bite back. For one, the fish may be highly endogenously toxic, meaning that the fish embeds poisonous compounds into its own essence, it’s own bodily tissues. Pufferfish are well-known for this approach, and many species have organs loaded with tetrodotoxin (TTX), a naturally-occurring, chemical Angel of Death so potent that it makes cyanide look like fucking ibuprofen. Preparing pufferfish for the passage between human lips takes all the insane, brow-beading, calculated finesse of disarming a bomb, but despite the supreme level of care of highly-trained culinary experts, every so often, people drop dead after ingesting the fish. Really damn dead. There are also the ever-present risks of conventional, bacterial food poisoning and infection with parasites like tapeworms and roundworms, both of which are more likely to occur in the less-than-cooked form of fish (my personal favorite state of fish).

Yes, you potentially need to watch what you eat when it comes to fish, whether you risk the slow march of mercury toxicity or a weekend hovering over the world’s unhappiest toilet. These risks are generally understood and expected.

What isn’t expected from your seafood? That you might get high off of it.

The phenomenon is called “ichthyoallyeinotoxism” or “hallucinogenic fish inebriation”; both are just jargony ways of saying that, somehow, the catch of the day has you hearing colors. Occurrences are uncommon, but there are plenty of baffling records, ancient and modern, of humans coming away from their sea-borne suppers with more to worry about than a bit of lemon wedge-fueled acid reflux. Like how to convince the grumpy, five-headed emu in the corner of the room that you don’t have any millipedes hiding under your fingernails.

“Alright, everybody, time to get weird!”

The actual inebriation scenarios vary greatly, between species of fish, and between intoxication events. Onset of symptoms can occur within minutes, or hours, and can last from a couple hours to more than a day. Sometimes there is gastrointestinal upset. Sometimes not. Often times, the sufferer endures a loss of coordination and balance, along with muscle weakness and a burning of the throat, but none of this is guaranteed either. Ichthyoallyeinotoxism, as a peculiar clinical feature, is more or less defined by the presence of vivid hallucinations and/or nightmares, and a capacity for intoxication in even cooked fish (suggesting that whatever compounds are responsible are also very heat stable). Typically, symptoms outside of the psychoactive effects tend to be pretty mild, and temporary, contrasting with the peripheral nervous system assault characterized by other forms of fish flesh poisoning (“ichthyosarcotoxism”).

Ichthyoallyeinotoxism has been reported in a diverse array of marine fish, but it has most regularly been associated with one species in particular; the Salema porgy (Sarpa salpa). This species of sea bream is common along the West and South coasts of Africa, as well as throughout the Mediterranean Sea. The Salema porgy is a rather conventionally-molded, petal-shaped fish that grows to about the size of a football, identifiable by glittery golden stripes that run the length of its body. The fish’s occasional ability to get humans hippy flipped has been recognized for ages, and Salema porgy (also referred to as “saupe”) was routinely eaten for recreational purposes across the Roman Empire. If these long-gone citizens were around today, they would likely regard Long John Silver’s as a glorious drug den franchise.

Scene from Seneca’s 36 AD theatrical tragedy, Reef Madness, or alternatively, De Otio Malus, “On Harmful Leisure”

For centuries, the fish (like many other species of ichthyoallyeinotoxic, or “hallucinogenic”, fish) has been called “dream fish” or “dream bream” for its psychedelic effects. The reputation continues until this day, however, since poisoning happens only on occasion, the Salema porgy is far more commonly consumed in the typical way fish are: as a food, not as a drug.

But, every so often, this backfires in spectacular fashion. In 2006, two case reports were published concerning recent ichthyoallyeinotoxism events caused by Sarpa salpa ingestion, both occurring along the French Riviera. In 1994, one of the unfortunate diners (a 40-year old executive) made the poor decision to partake in some baked Salema porgy while on vacation. Within hours, he was feeling shitty, and during the night, became a veritable puke fountain. Weakness overtook him, and in his ill state, decided to call an end to his vacation and drive home. This effort was brought to an abrupt end due to the onset of hallucinations. These weren’t the oft-depicted whimsical, psilocybin mushroom-driven phantasms full of fairies, talking trees, and a feeling of oneness with the universe. No, this poor son of a bitch was sidelined by a waking nightmare full of visions of “aggressive and screaming animals.” His mellow thoroughly harshed, and now unable to drive on account of seeing giant fucking bugs outside of his car, the man thought it might be a good time to get some medical attention. All his vitals at the hospital seemed kosher, except for the part where he was losing his shit because he was having the worst trip of his life, and after a short stay, he came back to reality…apparently, and thankfully, completely unable to remember the psychological hell his maritime meal had put him through.

The second individual outlined in the publication was a 90-year old man who purchased the Salema porgy from a local fisherman in 2002. Little did he know that his sweet, elderly soul was about to be catapulted through the stratosphere and straight into Never Never-do-I-ever-want-to-be-this-high-again Land.

Fish market? More like Phish market.

Within hours, he was bulldozed by auditory hallucinations consisting of human screaming and “bird squeals.” The retiree was apparently too terrified that the hallucinations were part of the sudden onset of a psychotic episode or mental illness that he told no one for the remaining three days of symptoms, which included frequent nightmares in addition to the general feeling of going bugfuck insane during waking life. It was only afterward that he recalled someone at the fish market saying something along the lines of “oh, just so you know…these fish are tasty but they can sometimes cage you in loop of mirrored realms full of hatred and the shrieking of dying universes” and decided to contact someone at the local poison control center.

Of course, the Salema porgy isn’t the only hallucinogenic fish out there. Sporadic records come from numerous other groups of fish, and one of these are the rabbitfishes. Rabbitfish, or “spinefoots”, are a group of fish native to the warm waters of the Indo-Pacific, and belong to the genus Siganus. The fish have a unique modification of the rear-facing fins; well-developed venom glands attached to spines making up the framework of the fin. These venomous barbs can be used defensively (and if the venom is used against humans, is not deadly, but can inflict excruciating pain), and are the origin of the decidedly more intimidating “spinefoot” common name.

“Do it. Call me Peter Cottontail one more time, buddy, and I’ll send you to the hospital.”

Despite their rather nasty pokey bits, rabbitfish are commonly fished for food by humans who live along the coral-lined shores of tropical coasts and islands. With consumption of these little, herbivorous reef fish comes the risk of hallucinatory poisoning. Residents of the Mascarane Islands (particularly Mauritius and Réunion) in the Indian Ocean, east of Madagascar, have reported regular, occasional instances of fish poisonings with symptoms consistent with the ichthyoallyeinotoxism seen with Salema porgy in the Mediterranean; loss of balance and equilibrium, nightmares, hallucinations, and mental depression, all in an absence of major peripheral neurological distress (usually associated with more typical (and serious) exposures to neurotoxins from food; trouble breathing, sweating, blurred vision, etc.). Apparently, the people of Mauritius and Réunion have been aware of this unique property of Siganus fish for some time now (enough so so that one species, Siganus spinus, is consistently referred to as “the fish that inebriates”), and local fishermen have associated elevated risk with certain times of the year in their archipelago home, and can avoid inadvertently taking a surprise trip to see just how far down the rabbitfish hole goes…

There are also records of hallucinatory poisoning by rabbitfish in the Mediterranean; specifically by the dusky spinefoot (Siganus luridus). This fish is native to the Western Indian Ocean, Red Sea, and Persian Gulf, but has been introduced across the Suez Canal in recent decades, although the symptoms were also similar to more “conventional” poisoning by ciguatoxins and maitotoxins (which cause ciguatera; a seafood-borne intoxication derived from ciguatoxins from single-celled marine algae which become aggregated in the flesh of food fish…most commonly associated with big, tropical, carnivorous fish like grouper, barracuda, snapper, and amberjacks).

Over on the other side of the globe, out in the West and Central Pacific, ichthyoallyeinotoxism is also implicated in hallucinatory poisonings, but often with different groups of fish.

Mullets (Mugilidae), odd, flat-headed fish found in warm waters the world over, have been reported to be ichthyoallyeinotoxic here in Hawai`i, as well as in the Micronesian islands of Kiribati. The toxins appear to concentrated in the head of the fish, specifically. At least some residents of the Republic of Kiribati, in recent times, would consume mullet heads with the intention of getting really fucking high. The hope was that eating a nice, fishy meal, kicking back on a tropical beach, and, er, “chasing the saltwater dragon” would allow for pleasurable hallucinations and vivid, otherworldly dreams.

Also, particularly in Kiribati, coral groupers (Epinephelus corallicola) and the banded sergeant-major (Abudefduf septemfasciatus) have been reported to occasionally cause hallucinogenic episodes, specifically in older members of the local population (the only age group that eats these species customarily; kind of like butterscotch hard candy and prunes here in the U.S.). Although, since only senior citizens eat these fish, and the high was described as a kind of “forgetfulness”, it’s not clear whether or not the issue is inebriation or run-of-the-mill senility. Then again, if people were accusing my old ass of spending my Golden Years getting toasty off the silly sushi, I might get awfully “forgetful” myself.
“What?! No, grandson, of course I’m not a stoner! That’s just Alzheimer’s.”

Sea chubs of the genus Kyphosus (pictured below), commonly eaten in Hawai`i in historical times (less so recently), have also been reported to induce intense hallucinations in diners.


Similarly in Hawai`i, convict tang (Acanthurus triostegus), a species of surgeonfish found throughout the Indo-Pacific, has been associated with ichthyoallyeinotoxic poisonings. The species (known as “manini” here in the islands) is abundant in nearshore reef habitat, and is readily identifiable by its markings, which resemble the stereotypical stripes of an inmate’s jumpsuit uniform…a criminal sentence most likely endured due to the fish spreading the scourge of drugs across their ecosystem.

Crime doesn’t pay.

So what is behind these hallucinogenic compounds? Why are only a limited group of fish associated with ichthyoallyeinotoxism, and why does it seem to only effect people relatively rarely? Other sources of hallucinogens in nature are, by and large, far more predictable than this. There may be variances in dosage between individuals, but many times, particular, entire species are known to have hallucinogenic qualities. Examples of these abound. Psilocybin or “magic” mushrooms and ergot (from which ergotamine, and eventually LSD, were isolated) are the hallmark psychedelics of the Fungi kingdom. The number of psychedelic plant alkaloids and other compounds, many of which play spiritual and cultural roles in societies around the globe, is incredibly high: mescaline from cactus (including peyote), bizarre and terrifically potent terpenoids like salvinorin A from the famed diviner’s sage, and DMT from dozens of vines and shrubs, are just a few major examples. DMT variants found in the toxic secretions of toads like Bufo alvarius also have consistently extremely psychoactive, hallucinatory properties. If we can identify specific plants, fungi, and animals that produce hallucinogenic effects, then what’s the deal with the weird, wishy-washyness of these hallucinogenic fish?

Since ichthyoallyeinotoxism is not a very common variety of food fish poisoning, and it presents so variably, we don’t really know much about it, or what is actually causing it, specifically. But, given how the phenomenon appears to be temporal, tied to seasonality in some locations, and is so highly variable, it is thought that the source is dietary. The fish are getting the toxins from their food, and much like with the mercury so many of us are familiar with, accumulating the stuff in their tissues. Since so many species that are causing these effects are herbivorous, it is likely the original source is marine algae.

This is strikingly similar to the most common form of poisoning from food fish, ciguatera. Ciguatera is caused by the uptake of a specific group of microscopic algae; dinoflagellates (chiefly the species Gambierdiscus toxicus). It accumulates in the food chain, compunding as one ascends, so that reef predators have the highest concentration of the toxins in their flesh (and are therefore most commonly reported to cause severe poisonings when consumed). Ichthyoallyeinotoxism does have a quite a bit of suspicious overlap with ciguatera, and it’s often hard to tell the two ailments apart from one another. For one, the species of fish that cause hallucinogenic poisonings are also commonly associated with ciguatera records as well. Secondly, the symptoms are incredibly similar, and both impact the nervous system in a myriad of bizarre ways. These similarities, and the lack of a specific source of the much rarer ichthyoallyeinotoxism has led some to believe that ichthyoallyeinotoxism is just one manifestation of ciguatera (which is caused by several known algal toxins).

However, the two maladies have distinct differences as well. Ciguatera is typically accompanied by furious digestive problems, muscle pains, lots of weird disruption of the peripheral nervous system (reversal of hot and cold sensations, electric charge sensations, and numbness) and only mild to occasional instances of hallucinations, whereas ichthyoallyeinotoxism has benign bodily impacts, with most effects on the central nervous system (the brain itself, leading to the hallucinations and nightmares). Also, ciguatera is notorious for long-term, pernicious effects, which can be severe enough to cause disability a decade or more out from the initial poisoning. Ichthyoallyeinotoxism, in contrast, abates completely within a few days with no reported latent effects in weeks, months, or years down the line. Hallucinogenic poisoning also turns up in places not typically associated with the normal range of the algae associated with ciguatera, like the Mediterranean (ciguatera tends to crop up most typically in the Caribbean and Pacific regions).

Others have postulated that the toxins might have their own, separate origins in algae like Caulerpawhich are habitually consumed by many of the more commonly hallucinogenic fish species.

Whatever is causing the occasional flaky, delicious acid trip in tepid seas, it shouldn’t be of huge concern to anyone reading this (or object of recreational interest; good luck successfully being lucky enough to be in the right place at the right time). Ichthyoallyeinotoxism remains an uncommon and enigmatic phenomenon, far less so than ciguatera or red tide shellfish poisoning (which are still not all that common, thanks partially to awareness campaigns and harvesting advisories during algal blooms). Mercury toxicity shouldn’t really be high on your list….that is, unless you are pregnant, or insist on eating canned tuna by the flat.

Honestly, the real source of caution seafood lovers such as myself should take is towards regulation of consumption. Many fisheries of popular food fish (Pacific bluefin tuna comes to mind) have been subject to extreme population reductions and are threatened with collapse. The effects not only impact human culinary lives and employment, but inevitably reverberate through entire marine ecosystems. Some stocks are in better shape than others, and are harvested in more sustainable ways than others. If you want to be selective with your seafood choices, your time and effort might be better spent keeping conservation in mind, not the risk of turning your mundane Thursday night into a disorienting, hallucinatory hellscape.

Image credits: Phish concert image, rabbitfish, sea chub (John Turnbull), convict tang

Intro image composite, modified from the following: Lionfish (Michael Aston), pufferfish, mandarin fish (Klaus Stiefel), lagoon triggerfish (Michelle Bender)

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Arachnids: Vinegaroons

This post is the sixth in an ongoing series on arachnids. Previously, this series addressed whipspiders, hooded tickspiderspseudoscorpionsharvestmen and solifugids. Additional posts on other weird, often overlooked or neglected groups of these creepy crawlies to follow. For a related chelicerate, but as far as science can tell, not an arachnid, see the post on sea spiders.

The vinegaroon.

By now, if you’ve been reading my continually-updated series on the underappreciated and less diverse groups of arachnids, you will have been exposed to an assembly of bizarre creepy-crawlies; among them, “headless” hooded tickspiders, library-squatting pseudoscorpions, manic, ever-hungry solifugids, family-oriented amblypygids, and amputation-prone harvestmen. Weird as these groups all are, few compete with the strangeness of the arachnids known as “whipscorpions”, “uropygids”, or “vinegaroons.”

These arachnids are members of the order Thelyphonida, a small group of arachnids comprised of only 100 species, dwarfed by larger orders like the Araneae (spiders, with more than 40,000 species) and the Scorpiones (“true scorpions”, with about 1,700 species). The order used to be incorporated in a now defunct classification known as Uropygi (which also included small, close relatives known as “microwhipscorpions”). “Uropygi” basically means “tail rump” or “tail rear” in Greek, which refers to the arachnids’ curious, thin, segmented “tail” extending from the back of their abdomen. It is this tail, or “whip”, combined with their general scorpion-like body shape, which is key to the origin of one of their common names; the “whipscorpion.” They are also known by their third common name, used frequently throughout the Americas, “vinegaroon”, which alternatively sounds like the most foul tasting Girl Scout cookie ever.

“Oh…oh god. What have I done?”

While vinegaroons have a scorpion-like body shape, with their flat, extended abdomens and spiky, clawed pedipalps (those pincer appendages in front of the face), they are not closely related to scorpions at all. As far as we can tell, they are most closely related to things like amblypygids and spiders, and are in a separate subdivision from things like scorpions, camel spiders, and daddy-longlegs, which make up a proposed grouping called Dromopoda.

Vinegaroons are found in the warmer latitudes of North America, throughout Central and South America, as well as subtropical and tropical Asia (and a lone species found in tropical Africa). The center of their diversity appears to be in Southeast Asia. They, in true arachnid form, like to hunker down in humid, dark places, which usually requires clawing out a burrow in the dirt with their pedipalps. Many species are found in forest habitats of varying moisture, but some live in arid habitats. One of these is the largest species of vinegaroon, Mastigoproctus giganteus, with a body about as long as a credit card, which lives comfortably in the desert and semi-arid tracts of the southern U.S. and Mexico, but tends to only be active during the wetter months of the year.

Vinegaroons are entirely nocturnal, and emerge from their dank holes in the earth nightly to stalk hungrily and ominously over the Land of the Tiny. They are exclusively carnivorous, and feed primarily upon other arthropods, like crickets, cockroaches, and millipedes, which they pin down with their beefy, scorpion-like, wire-cutter pedipalps. They are also equipped with a sharp spine on the inside surface of the claw, which is more or less a barb, immobilizing the prey and paving the way for the merciless crushing of their prey’s brittle exoskeleton, allowing the vinegaroon to leisurely lap up the critter’s hemorrhaging fluids like a cat at a water dish.

The hard part, though, is finding the food in the first place. Vinegaroons have eight small eyes, two at the front of the head segment (the prosoma) and three flanking each side, but the eyesight they provide is so fucking poor the worthless things might as well be pimples. To make up for their myopic failings, vinegaroons successfully navigate their witching hour escapades by tactile mastery. They, much like their distant cousins the camel spiders (solifugids), only use their hind three pairs of legs for walking; their front pair have evolved into long, thin, highly-sensitive feelers that scan the ground in front of the vinegaroon. It would seem that somewhere early in its evolution, the vinegaroon must have looked at insects and their antennae with much envy, because these modified front limbs look like the imitation, off-brand version of what everything from beetles to bumblebees have been proudly waving around on their heads for eons. In this way, vinegaroons sense their environment similarly to their close relatives, the amblypygids, using their delicate front limbs as a pair of white canes. Further contributing to sensory input is their “tail”, a long, straight, segmented rod (also referred to as a “telson”, which is a term also used for the “tail” of crustaceans like lobsters and shrimp). The telson is used to feel around at the back of the animal, and surely functions as an adaptive safeguard against the “Kick Me” sign prank.

But woe be unto those who dare to stray too close to the vinegaroon’s caboose. These arachnids don’t have the venomous bite of spiders at the front, nor the deadly sting of scorpions at the back. Their pedipalps can deliver a bit of pinch, and the worst their telson can do is give a gentle tickle. It would appear as though the vinegaroon is something of a sitting duck, nothing but a helpless, crunchy, eight-legged chicken nugget for the world’s passing raccoons and lizards to casually inhale. But the vinegaroon has a unique trick up its sleeve geared towards keeping it unharassed and uneaten.

The vinegaroon is a squirter.

Vinegaroons are armed with glands located right at the junction of the rear body segment (the abdominal segment, or “opisthoma”) and the base of the telson. These glands (the “pygidial glands”) produce a liquid mixture of a number of chemical compounds, but the stuff is primarily acetic acid and caprylic acid in many species. You may know acetic acid as the key ingredient in vinegar, which is essentially 5% acetic acid by volume, which gives it its sour taste and characteristic odor. When threatened, vinegaroons jettison the watery contents of these glands through a pair of pivoting turrets, mounted on either side of the base of the telson in a spurt that can each about a foot away in any direction. With just enough agitation, the vinegaroon contracts the muscles around its dual tanks, and lets the cocktail loose, sending a wild, flailing stream of vengeance arcing through the heavens, like some drunk bastard using a urinal during an earthquake. It is the resulting noxious stink from these acidic emissions, reminiscent of common, household vinegar, that is at the origin of the “vinegaroon” name. The smell is particularly strong due to the concentration of acetic acid in the spray, which can be 15 times more concentrated than in vinegar. The video embedded below shows how this spraying looks up close, at around 2 minutes in:

I can hear the scoffing already. Really? That’s the defensive response? A stinky water gun? What’s it going to do, turn an attacker into a pickle? Some scorpions, like those of the “man-killer” genus Androctonushave such horrifically venomous stings, that a defensive strike can incapacitate or kill animals as large as humans. Some spiders, like the Sydney funnel-web, can potentially deep-six your ass if it insists on getting bitey. But the vinegaroon’s so-called “defensive behavior” has all the ferocity of an infirm chihuahua dribbling on a carpet. Other arachnids can do wonderfully nasty, painful things to get predators to turn tail…while this firehose-assed jackoff over here is what, adding zest to a salad at Olive Garden? What would a vinegaroon-themed supervillain even do? Terrorize reservoirs of baking soda sitting underneath paper mâché mountains?

“Oh, human, you will rue the day you picked up the Sprinkle Master…prepared to be….wetted…”

The vinegaroon’s pungent piddling isn’t just an uncomfortable distraction; it is actually a well-honed deterrent. For one, the dual flesh faucets that spray the jet of chemicals can be rotated in just about any direction, and can quickly be aimed relatively accurately in the direction of a harasser. The goal isn’t to get the predator to wrinkle its nose and recoil at the sour stink, but to get the ass spritz into the eyes, nose, and mouth. This is a strategy not unlike what spitting cobras employ for dissuading aggressors. The spray, in most species, isn’t concentrated enough to do much to skin, especially if that skin is covered in fur. But the acid mixture is irritating to mucous membranes, and a shot of this crap in the mug will go over like lemon juice eye drops and jalapeno mouthwash. The shit burns.
There’s also evidence of the presence of 2-ketones in the sprays of some species of vinegaroon, specifically 2-heptanone, 2-octanone, and 2-nonanone…all of which can function as potent organic solvents. The presence of these solvents (which help dissolve organic compounds, like the acetic acid, in other organic compounds…which includes everything you are made out of) in the sprays has shown to increase the effectiveness of the acetic acid, with the spray actually managing to briefly sting human skin. The 2-ketones act as an “enhancer” for what is normally a benign acid for large animals.

If the proctological can of Mace doesn’t work, there’s always good, old-fashioned claw clappin’ and scrappin’. The pedipalp pincers aren’t deadly to anything larger than a house key, but a nip on the face of a lunging mammalian assailant might be enough to convince them to reconsider. When threatened, vinegaroons will normally strike a defensive pose with their pedipalps outstretched and ready to tussle, with their opisthoma and telson arched, prepared to turn on the Pain Sprinkler.

“Come at me, bro. I can do this aaaallllll fucking day.”

Assuming these blind, wizzing wizards fend off enough toothy jaws with their stanky squirts to make it to adulthood, they can get right on with the baby making…but not before an arduous courtship display.

Vinegaroons engage in an exhausting, complicated, 13+ hour-long marathon of multi-stage foreplay prior to getting on with the rogering. It starts off with roving male encountering a female, and him chasing her down and grappling her with his pedipalps. The two of them then appear to spar with one another, gripping, shoving, and throwing each other around. It’s so….sweet? This bit of love wrasslin’ can be cut short at around a minute, or this stage, which may function as an evaluation of “worth” in a partner (“is he/she a good, strong mate?”), can continue for hours. If the female is receptive to a, errrr, “second date”, she’ll signal that they can proceed by sticking her first pair of sensory limbs in the mouthparts of the male and wiggling them back and forth. This acts as a “tap out”, and the couple proceeds to the next step in their relationship. At any point prior to this, she may signal that she’s not down to clown, and with a subtle, aggravated flick of her sensory legs, she peaces the fuck out and courtship ends.

The second phase involves dancing. Not even joking. The male still grips her delicate sensory limbs in his mouthparts (“chelicerae”), and, face to face, he drags her around, back and forth, using his muscular pedipalps. The female follows his lead, continuing to evaluate him as a mate. The sensual display is akin to something out of Dirty Dancing, except this version of the mambo has Jennifer Grey’s fists wedged deep in Patrick Swayze’s mouth. This part lasts somewhere on the order of three or four hours.

“Nobody puts Baby in a burrow.”

If both partners are still ready to continue towards the finish line, the male while have typically edged the two of them into a safer location (like a burrow). The male, still with the female’s sensory legs embraced by his mouthparts, rotates so that he’s now riding on top of her. They stay like this, poised awkwardly over each other like players in a game of Twister, for another several hours. During this time, the male manufactures a spermatophore (a dense sac of sperm) inside of his abdomen. When this is over, the male deposits his payload on the dirt in the form of rigid block of reproductive material. He then carefully maneuvers the female over the spermatophore, and takes the two attached sperm packets from the spermatophore framework, and shoves them into the female’s gonopore (genital opening). When the female is ready, she signals by opening her clawed pedipalps, and the male promptly releases her legs from his mouthparts, and wheels around to grasp her soft abdomen. For the next few hours, the male massages the sperm packets with his pedipalps, and it is thought that this helps the sperm actually disperse into the female’s reproductive tract. Eventually, the deed is done, and they uncouple and go their separate ways. Unlike in many other arachnid groups, post-coital cannibalism doesn’t really seem to be a thing in vinegaroons. After a casual boinking with a disproportionately passionate preamble, they mutually part paths.

The female then carries fertilized eggs inside of her for a few months. Before laying as many as three dozen eggs, she seals herself up in a burrow for safety. However, instead of laying a clutch that sits on the floor of the burrow, she contains them in the sac that adheres to the bottom surface of her opisthoma. She continues this voluntary house arrest for another few months. Did I mention that she refuses to eat? And that she arches her abdomen in such a way that the giant broodsac can’t touch the ground? FOR MONTHS. Say what you want about the difficulties of human gestation and what our mothers went through in pregnancy to birth all of us…but mama vinegaroons endure the equivalent of carrying around a garbage bag full of bowling balls with nothing but your clenched ass cheeks for an entire college semester.

“Oh, you do Kegels? That’s cute.”

Eventually the eggs develop into “post-embryos”, which is a name that doesn’t adequately illustrate how much these larval creatures look like albino, baby, gummy squids.

Tapioca pearls with legs. Lovely.

These baby vinegaroons climb onto their mother’s back, where they latch on for dear life with sucker-like organs. There they remain for yet another month. Eventually, they have their first molt, and begin to disperse away from the mother and begin foraging upon small insects and mites. Once seasonal rains arrive, and the young have all managed to develop hardened exoskeletons, the mother, famished, bursts out of her subterranean cocoon to get her fat reserves back up again. Much like their relatives, the whipspiders, vinegaroons engage in a higher level of maternal care than what is seen in many other arachnid orders. The mother will abstain from eating her babies unless in dire need of sustenance, and cohabitates with the young, first-molts in the burrow for a short while. Whether or not the mother, in nature, actually provides food for the young during this time is not currently known.

Thelyphonida, an enigmatic and rarely encountered order of arachnids, is represented by a single family in modern times. The vinegaroons are an ancient group, with fossilized, relatively unchanged representatives stretching back 350 million years (in the Carboniferous era), 100 million years before the earliest dinosaurs strode Earth. Today, only a small number of species are still around. These dark, glistening, hard-shelled, silent travelers of the night quietly assist in reducing numbers of pests like cockroaches and termites. These acrid skunks of the arachnid world are oddities, with their trifecta of sensory feelers and unusual acetic acid nozzles, and while they might appear dangerous or foreboding, if you are so lucky to encounter one in the wild, remember that the worst these little guys can do to you if you get too close is stink up your shoes.

Image credits: Intro image, vinegaroon in hand, defensive vinegaroonvinegaroons dancing, female vinegaroon carrying broodsac, vinegaroon with post-embryo young

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Arachnids: Solifugids

This post is the fifth in an ongoing series on arachnids. Previously, this series addressed whipspiders, hooded tickspiderspseudoscorpions, and harvestmen. Additional posts on other weird, often overlooked or neglected groups of these creepy crawlies to follow. For a related chelicerate, but as far as science can tell, not an arachnid, see the post on sea spiders.

The solifugid.

This group of fleet-footed arachnids is known by many names across the globe. Wind scorpion. Camel spider. Sun spider. Sun scorpion. Unintelligible screaming and cursing. All of these refer to members of an enigmatic order of arachnids; Solifugae. The name of this order, derived from Latin, means “those that flee from the sun”, an acknowledgement of their habit of chasing shadows in an attempt to stay cool in their predominantly hot, sunny, and arid native habitats. Despite their frequently used common names which identify them as some sort of breed of spider or scorpion, solifugids (a more accurate identifier of the arachnids within the Order Solifugae) are most certainly a distinct, separate animal from either group. They may have the long, athletic legs and noticeable jaws of spiders (Order Araneae), and the elongated body, coloration, and desert aesthetic of the scorpions (Order Scorpiones), but the 1,000 species or so of solifugid occupy their own lonesome twig on the arthropod family tree. It is generally thought that Solifugae is a part of a larger subdivision of arachnids, called Dromopoda, which also includes scorpions, pseudoscorpions, and harvestmen (daddy longlegs); specifically, combined analyses of the genetic relatedness and shared morphological features of these critters have also linked scorpions, pseudoscorpions, and solifugids together in a grouping dubbed “Novogenuata.” Although, comparative studies on the male genital system have also suggested that solifugids might have a more complex evolutionary history, showing more similarities with mites and ticks in some ways than with their supposed close relatives, the pseudoscorpions. This confusion of what makes a solifugid a solifugid, and its relationship with the rest of the arachnids, would be greatly assisted by fossil evidence, but the fossil record for the Solifugae is pitifully scant, with a few dubious, incomplete, vaguely solifugid-like specimens dating back to about 330 million years ago…and only a few instances of unambiguous solifugids showing up about 300, 115, and 50 million years ago. Most importantly, the earliest stages of this group’s evolution are currently lost to us.

Whatever they are in the grand architecture of the arachnid clan, they are widespread, gravitating towards hot and dry regions of the subtropics and tropics the world over, omitting their presence from only the continents of Antartica and, surprisingly, considering they would fit right the fuck in there…Australia. And wherever they make their residence, they have a very powerful effect on the humans that encounter them, and they have for an incredibly long time. Solifugids, to put it lightly, have an “imposing” appearance and demeanor, with their huge, sharp, pinching jaws, sizable mass, and ungodly overland speed. Consistent first impressions full of everything ranging from a bad case of the all-overs to panicked, wild boot-stomping has undoubtedly earned them immediate recognition as a being assuredly, terrifyingly divergent from other many-legged beasties since antiquity, with the Greeks dubbing the monstrous arachnid “phalangion”, decidedly separate from “arachne”, the spider. More recently, there are accounts of soldiers stationed in North Africa during both World Wars who would pass the time by pitting captive solifugids against each other, or against a scorpion (because why not, I guess), in a fight to the death in possibly the smallest, ugliest, and leggiest gladiatorial showdown of all time.

I’m thinking a 6-inch tall Joaquin Phoenix will give the scorpion a thumbs down.

These brutal spectacles involving dueling “jerrymanders”, another name for the solifugids, were enthusiastically gambled upon, because of course they were. Also, in regards to the aforementioned moniker, if there’s any animal that I could envision being spiritually associated with the deceiptful, ethically impoverished, slimy act of manipulating voting districts, it’s the solifugid…an animal that looks like it would skitter up your leg and chew and burrow its way into your taint if you so much as looked at it sideways.

If you are a solifugid reading this right now (small chance, but you never know), I have to apologize for the upcoming dosage of Truth; y’all ain’t pretty. Spiders and scorpions at least have some measure of gracefulness and an aura of venomous allure…solifugids look like someone tried to cross-breed a centipede with a walrus, and then set it on fire when it came out looking like damnation itself. It is this severe case of “face-made-for-radio” that has allowed these animals to continue to be, to this very day, viscerally upsetting to the point of inspiring mythology and fanciful stories. Although solifugids are routinely found in the American Southwest (where they are called “sun spiders”), many troops (particularly U.S. troops) stationed in the Middle East during the Persian Gulf War of the 1990s and more recently during the Iraq War, encountered these arachnids for the first time…and it wasn’t long before tall tales sent home, and subsequently inflated through the power of the Internet, exaggerated solifugids to preposterous heights. Urban legends in the form of obnoxious chain emails and memes floated around online message boards about these animals cast them as having supernatural capabilities…running fast enough to keep up alongside military vehicles and capable of leaping from the ground and onto the chests of full grown men, screeching and hissing, clacking their drool-slathered pincers (is there any other way?). The name “camel spider” was commonly tied to a claimed habit of disemboweling sleeping camels under the cover of night with the aid of a paralytic venom. The icing on this sci-fi monster cake was the assertion that they would attack and paralyze soldiers, and lay their eggs inside the skin of the unwitting human incubator, ala parasitoid wasps (or Alien…that too), only to have the babies explosively emerge from inside the poor soldier weeks later like a bunch of bloody confetti erupting out of a piñata.

Feeding into this are the highly-circulated photographs sent back to the States, often with the solifugid in forced perspective to appear larger than they are in-person, or conducting some act of eight-legged, predatory horror upon a prey item….conveniently with no real sense of scale.

Agreed. Optical illusions keep me up at night.

…and then ask you to give a public speech with inadequate time to prepare. Horrifying!

Of course, just about all of this is hyperbolic nonsense. Solifugids are intimidating, yes, but they pose absolutely no danger to camels or any other large mammal, humans included. This reputation has left the proud, albeit unsightly, Order Solifugae unfairly maligned. I’ve drafted (below) what I think is a more appropriate meme depicting the reality of the unjustly despised, feared, and ostracized solifugid, about which I’m confident the rest of the Internet will give approximately no fucks.

“Don’t wanna be…aaaallll byyyy my-se-e-lf….”

The truth is, solifugids aren’t a hyperaggressive, ancient evil, scouring an exotic, desert landscape in a lustful search for the least leathery leatherneck neck to sink its fangs into…though they certainly look the part. What they really are, however, are an active group of predators that have been fine-tuned by the selective pressures of their harsh environment to produce some incredible, fundamentally badass characteristics. Solifugids have a unique biology that deserves a fair shake at deconstruction and illumination.

Solifugids follow the general arachnid bauplan fairly conservatively, with two well-defined main tagmata (body segments); the prosoma, at the front, containing the “head” and connection points for the eight pairs of legs, and the opisthoma, the meaty, egg-shaped abdomen at the rear. The most obvious, and frightening, distinguishing feature of these animals is their chelicerae…the duel pair of vertically-oriented pruning shears that engulf their face, often reaching sizes larger than the entire prosoma itself. In many other arachnid groups, chelicerae serve as the humble articulating mouthparts, tucked neatly around the mouth hole and mostly out of sight. But in solifugids, the chelicerae are expanded into huge cutting tools, lined with knobby teeth-like projections, resembling a pair of devilish eagle beaks. The entire “head” region of the prosoma, encapsulated by a raised, rounded dome, essentially serves as nothing more than the powerhouse for the chelicerae, and is packed with bulging sets of muscles used to manipulate the double sets of jaws. In fact, the characteristic hump that contains these muscles at the base of the chelicerae is the origin for the “camel spider” name, not any fallacious murder of cigarette company mascots.

Joe has nothing to fear from solifugids. Emphysema, on the other hand…

If you’re thinking that with all that special muscle devotion and attachment, these chelicerae would be pretty powerful, you’d be right on the money. Solifugids don’t possess the fictional paralytic venom of urban legend to take down prey…the serrated bolt cutters grafted onto their face do just fucking fine. Solifugids are rapacious predators, with incredibly high metabolisms, and a need to track down, capture, and process food quickly. Their ecology, diet, and physiology have led to the evolution of mouth-bound machinery designed to carve and mulch up prey as quickly and efficiently as possible. This is not dissimilar from the likely reason for the evolution of specialized teeth for food processing in mammals; comparatively high metabolisms need to be able to acquire and break down fuel sources immediately and completely. In the same way, solifugids have become eating machines, rapidly devouring anything they can pin down…which is a large number of things. Larger species, sometimes reaching several inches in length, aren’t limited to the numerous insects in their equatorial habitats, and frequently tear into smaller vertebrates with the unrestrained enthusiasm of a sugar-high 6-year old, armed with scissors, on paper snowflake day in arts and crafts. Lizards, mice, baby birds…none are safe from Greedy Gonzales and his Terrible Twins. The chelicerae are more than robust enough to splinter more fragile things…like bones. For this reason, humans that unwisely pester solifugids and end up getting bitten report intense pain and often the drawing of a great deal of blood; most bites from arachnids and insects hurt due to injected proteins from the saliva, but solifugids provide pain with pure force and physical damage.

Humans have nothing to fear, really, from solifugids. But if you’re anything smaller than a baseball? Be afraid. Be very, very afraid.

With rapid back and forth rending of flesh and viscera, the solifugid uses their “cheliceral mill” to pulverize animals as large as itself (not that hard to accomplish when half your goddamn body is jaws), and slurps up the resulting juices and gelatinized remains.

Jesus, man! All he wanted to do was save you 15% or more on your car insurance!

The chelicerae may be excellent tools for bloodily dismembering still living, kicking, and squealing prey, but they also have other important roles to play in the life of the solifugid.

Although solifugids tend to tolerate long periods of extreme heat and aridity better than other arachnid groups, they make life easier on themselves by avoiding some of the harshness of the desert by getting the hell away from the baking solar radiation. They do this primarily by being largely nocturnal, but also by taking cover in the day by seeking out shadows, or digging burrows. Of course, since solifugids haven’t invented shovels (yet), they use the next best thing…their monstrous chelicerae. It probably isn’t surprising that something that has utility in sawing through muscle and bone might also be good for sawing through soil. The solifugids claw at the loose, dry dirt with their mouthparts, only turning away from the laborious activity to clear out their excavation of what they’ve dug out. This is a method used by many burrowing animals, including naked mole rats, which dig their network of burrows using their sharp incisor teeth (and have actually evolved a flaps of skin that keep their mouths from filling with dirt as they work). Observe this industrious little fellow below:

The chelicerae are also used in defensive measures against predators even nastier than they are, and it’s not in the way you think. While, yes, they can and do use their jaws to strike out and give a well-placed nip at an attacker, the chelicerae also have a role in a warning system to would-be fuck-with-ers. This is done through the generation of noise through vibration of physical components of the interior surfaces of the chelicerae against one another. Solifugid chelicerae can be thought of musical instruments of sorts.

Ah, nothing like the sweet sound of the guillotine guitar.

This generation of sound from vibrating body parts is known as “stridulation” and it is common in other arthropods, like insects. It’s perhaps familiar to most folks as the origin of the “chirping” of crickets and grasshoppers, which is caused by the running of the surfaces of the wings across one another, and allowing comb-like structures to contact and rub along each other, producing the sound. But stridulation is also found in numerous groups of beetles, as well as arachnids like spiders and our lovely solifugids. All you need are two body parts, known as “stridulatory organs”, to rub against each other to make the noise. This often depends on something scraping rapidly along a finely-ridged surface, generating vibration as it does so. This is the same kind of action that allows fingernails to produce sound when running along a washboard, or for the needle to relay embedded musical recording information as it moves along the tracks on a vinyl record (sound which is then amplified).

The interior surfaces of the solifugid chelicerae are equipped with two major stridulation components; a plate covered in microscopic ridges (a “file”) and a set of stout, forward-facing bristles. The sound is generated when the chelicerae are pressed together and slide past each other, causing the bristles to drag down the file on either chelicerae….and it ends up sounding like this:

While that may sound like the world’s most perturbed Velcro sneaker, scientists believe it has a role in keeping solifugids safely uneaten. Squeaking produced by solifugids in laboratory settings seems to occur in response to perceived threats, and is acoustically similar to the noises made by other arthropods that use warning noises against predators. It has been suggested that solifugids stridulate as a form of bluffing. Solifugids aren’t toxic, and don’t create any venom, but it is highly advantageous to convince predators that they are. One species of solifugid in the genus Galeodes from west-central Asia might use its hissing stridulations as a way of mimicking the noises made by venomous snakes that it shares its habitat with, like the blunt-nosed viper (Macrovipera lebetina) or the Siberian pit viper (Gloydius halys). If you have a bag full of nothing in the face of immediate danger, it might be a worthwhile idea to confuse your enemy into thinking you’re someone who does…and a local, highly-venomous snake is a damn good place to start.

The abilities afforded by the chelicerae don’t stop with stridulation either, because apparently these things are like a damn Leatherman of the arachnid world. Male solifugids have structures on the tops of their chelicerae called “flagella” that look like long, swept-back horns or rigid tentacles. Seeing as how only males possess them, it is thought they have some sort of role to play in solifugid sex, but to be honest, no one really knows what the hell they do. I suppose figuring that out would require researchers to get up close and personal to the gnashing jaws of a sexually ravenous solifugid. I mean, I understand why they haven’t quite unlocked that secret yet because have you SEEN those fucking things?

Aaaaaand fuck it, I’m going home.

So, obviously, in solifugids, the head is more or less a battery of powerful tools for survival in the barren desert wastes. Just the chelicerae alone function as steak knives, a backhoe, a furious kazoo, and…maybe something related to sweet, sinful, stomach-churning, solifugid sexual satisfaction? But the legs and body of these critters are equally important and full of exquisite adaptations worth addressing.

Scorpions and solifugids are close relatives, and have both become masters of the desert biome over hundreds of millions of years. However, their strategy for survival here is very different. Scorpions have a suite of adaptations to minimize their output of energy and water. Many species can hunker down under a rock and remain in a type of stasis without eating or drinking for very long periods of time. They move across the desert deliberately, and under the cool of night, and use their venomous sting as a conservative means of procuring food. Paralyze and kill the quarry immediately, so that you can be sure it can’t get away or put up a fight, and subsequently cost you the precious energy. Solifugids took the opposite approach, and live by a mantra of MOVE MOVE MOVE EAT EAT EAT. Solifugids, as I’ve mentioned, have incredibly high metabolisms, and compared to scorpions, ludicrously high growth rates. They live their lives on the fast track, taking the strategy of “getting big quickly and reproducing before the desert has the chance to kill you.” Solifugids are all about running around and killing soft, vulnerable things, and outside of their gigantic chelicerae, they have key adaptations for sprinting around at blinding speeds, maximizing each kill’s energy yield, and making damned sure every meal and mating attempt goes according to plan.

Understanding how solifugids navigate through their world is key to understanding how they manage to survive and consume so much in a place with so little resources to offer. Solifugids only use three of their four pairs of legs for locomotion. The first pair of legs, up near the head, are thinner and more delicate, and are usually held just off the ground and act like antennae, rapidly trailing and sensing the environment via touch as the solifugid motors along. In front of these legs are a pair of pedipalps, appendages that look like legs, but are not, and are more often associated with the mouthparts in arachnids (the pedipalps of scorpions, for example, have been modified into the pinching claws). In solifugids, they are huge and elongated, and often look so much like legs that people regularly report sightings of solifugids as “big, ten-legged spiders.” These pedipalps are also instrumental in sensing the path directly in front of the solifugid. With three pairs of appendages powerfully propelling the animal forward, and two pairs elevated in the air, the solifugid is like some kind of arachnid centaur.

And much like the mythical beast, solifugids are renowned for their elegance, dignity, and…er…beauty.

Solifugids move about in this way insanely quickly, flying over the hot sands at 10 mph (16 kph)…which is quite a feat for an animal smaller than an iPhone. While there are other invertebrates that, for their size, are faster than solifugids (for example, the pint-sized tiger beetles come to mind), nothing without bones really comes close to these speeds, which are close to what an adult human can accomplish at a sprint. So how do they manage to do this?

The answer may come from how they fuel their bodies with oxygen. Solifugids, along with the Opiliones (harvestman/daddy longlegs) and the pseudoscorpions, don’t have book lungs, which are the typical respiratory tissues found in arachnids. Instead, like harvestmen and pseudoscorpions, they have a network of small tubes running in and out of their bodies that allow the exchange of oxygen and carbon dioxide to occur. This system of tubes (“trachea”) are very highly developed in solifugids, much more so than in other invertebrates with tracheal systems. Solifugids also have multiple pairs of spiracles (holes) that pump large volumes of air in and out of this network with great efficiency. These bastards are able to visit blistering, swift death upon everything that creeps and crawls under the desert sun because when evolution was passing out engines, they got the 8.0 liter, quad turbocharger, 64-valve, 1,300 horsepower version. Solifugids aren’t so much animals as they are wire cutters super-glued to a rocket.

This constant incredible athleticism means that the solifugid must carbohydrate load 24/7, and make sure that if it runs down lunch, it better come out on top. Part of this is facilitated by the vice-like grip of its chelicerae, but that requires getting close enough to chomp down. This is where the pedipalps come in, which have eversible suction pads on the tips. These little structures stick right on the prey in mid-chase, allowing the solifugid to get a grip and pull the hapless victim straight into the torturous embrace of its esurient maw.

To get an idea of what this would be like, imagine you are a lone agama lizard, taking a night stroll on the flanks of sand dune in the middle of Sahara in search of a wayward beetle or two to snack on. Then, you hear something clambering over the ridge of the sand dune…and it’s approaching fast. Really fast. Before you can even react, a hideous vessel, festooned in flailing jaws and legs, clears the top of the dune, and races down after you. You can’t get your footing on the loose sand in time, but the solifugid, dancing on the shifting surface with its light, hairy feet, has no problem at all. You turn to flee, and just as you do, terror grips you as you see those fucking toilet plungers of death eagerly reaching out towards you. You skitter down the dune, sand flying, your little lizard heart pounding. The solifugid, aided by gravity, gets closer, bearing down on you, a vast tank driving a flurry of clacking car compactor claws, slicked with saliva, horrifically screeching as they rub past one another. Suddenly, you feel one of the suction cups adhere to your scaly side with a sickening wet pop, and you are yanked backwards. The sound of the rustling pincers to your back ceases right before they come down on your belly with tremendous pressure. You let out a pitiful yelp as the solifugid silently, coldly, articulates a massive jaw over your head. It easily collapses your skull, and everything goes black.

That’s the day to day reality for anything small sharing the desert with these animals.

Those nifty little suction pads? Yeah, those are perfectly suited for grabbing flying insects out of the goddamned air. Solifugids will take and eat anything they damn well please. Flying away only prevents the inevitable in the desert.

Solifugids are apparently so voracious, that they are known for eating themselves into a bloated stupor, so swollen with food they can’t even move. Their soft, stretchable abdomens expand with liquefied food like a water balloon attached to a sink faucet. This allows them to obtain as much food energy as possible in a very short amount of time, a skill I learned and exploited whilst around free food in my college years.

In addition to those weird flagella on male chelicerae, there are other organs adorning the Solifugae that are a complete mystery to science. I’m specifically talking about a set of organs on the underside of the last pair of legs that jut out from the exoskeleton and are shaped like ghostly white ginkgo leaves, or mushrooms.

Whoa. You, uh…should have a doctor look at that, bro.

They are called “malleoli” and while scientists are pretty sure they are sensory organs, they don’t really have any idea what they are sensing, or how they are doing it. The odd, fan-shaped structures might be sensitive to vibrations traveling through the ground, or to chemicals in the air, but science, as of right now, has given the colorless, gummy umbrellas a collective shrug.

If a solifugid manages to violently consume its way out of childhood and grow to full, reproductive age, it may be struck by the urge to settle down and have a clutch of baby camel spiders all of its own. But reproduction is easier said than done in the world of the solifugid. These are purely solitary hunters, and because of this, mating opportunities don’t exactly spring up naturally like they do in socially-competent humans (er, well, most humans).

“I walk a lonely road, the only one that I have ever known….”

If you were a solifugid, being a loner for much of your life would actually be a very wise idea. You see, it turns out that an animal that instinctively looks at anything in its own size range as a meal doesn’t tend to play nice with other solifugids. These creatures are not big on long term relationships…or short term relationships…or the equivalent of a coffee date…….or anything. What they (and by they, I mean the female solifugids) are a fan of is ripping apart and devouring anything that tries to mate with it. That unstoppable appetite is indiscriminate, and well-meaning gentleman callers don’t get a free pass. Solifugid mating protocol is made exceedingly complicated by the ever-present threat of sexual cannibalism…which in reality is nowhere near as hot as it sounds, pervert.

From the perspective of a male solifugid, female solifugids are gargantuan monsters twice their size, insane with insatiable hunger, and able to cleave them in two in a fraction of a second. But…they also want to have sex with that gargantuan monster, beautiful creature that she is. In order to get around this seemingly insurmountable dilemma, in many species of solifugid, the males have acquired a number of special adaptations, both physical and behavioral, that allow them to sow their seed and make it out alive.

A conventional approach, used by many species of solifugid, is for the male to excrete a spermatophore (a dense sperm packet), which is then placed on the ground near the female. The male then “courts” the female by some very cautious massaging and dancing around. This is less “taking the lady out for a nice meal” and more “dangling a steak in front a tiger’s face.” Once the hungry hungry horror is lured into the perfect position, the male takes a deep breath through his tracheal spiracles, and does the unthinkable. He grapples the female, holding onto her back tightly with the suction pads on his pedipalps, and supplexes her onto the spermatophore, which he then plasters into her genital opening. This is like if you needed to stick a wad of gum on the belly of a grizzly bear, and you tried to do so by tackling it from behind and attempting to pull it to the ground, equipped with nothing but a couple of suction tip Nerf gun darts to increase your grip. After the objective is complete, he lets his immeasurably pissed “partner” go and books it in the opposite direction as fast as his post-coital legs can carry him.

Males in some other species, especially ones with a high degree of sexual cannibalism, have to struggle even more to pass on their genetic material. Observations of mating behavior in species of Galeodes and Gluvia, in which sexual cannibalism runs rampant, have illuminated a complicated and life-threatening bit of “coercive” copulation that males must endure. And by “coercive” I mean “forced.” In order to subdue the female long enough to slap some baby batter in her genital opening, the male employs a bit more than just a fancy wrestling move. He approaches carefully, with or without some strokes from his pedipalp, and then lunges, chomps down on her legs and abdomen, chews at her genitals, hooks and locks her hind legs with his own, and after she’s pinned, he transfers the spermatophore. There is no cuddling afterwards.

When solifugid children ask their parents where babies come from, the response they receive is a flat, solemn “Pain, child. Pain. All of life is pain.” And then the parents decapitate the young and feed upon its kidneys, because, you know…solifugids.

Modified from Fig. 2 in Coercive copulation in two sexually cannibalistic camel-spider species (Arachnida: Solifugae). M. Hrušková-Martišová, S. Pekár, and T. Bilde. 2010. Journal of Zoology. Vol 282: 2, pp 91-99

These encounters can get so heated that males can inflict substantial injuries upon the female, including puncture wounds, scrapes, and occasionally the severing of an entire limb. These kinds of “love amputations” are apparently just a ho hum part of the savage life of the solifugid.

Mating is so treacherous for male solifugids that they’ve actually evolved a series of physical adaptations to make their screw-jitsu moves that much more successful. For one, males in these sexually vicious species tend to have proportionally longer legs and small bodies, allowing for greater agility and an increased reach, which helps in keeping Princess’s unholy gob of horrors as far away as possible. Males also have stronger, stouter, pokier spines along their pedipalps, which are likely used to hold on to Miss Buckin’ Bronco until the deed is done.
Yes, solifugid sex is so violent that only males that have a natural, morphological edge (like built-in crampons, for fuck’s sake) in going head to head with the most fearsome thing in their world (a hungry, full-grown female solifugid) are able to send their genes into the next generation.

Solifugids are undoubtedly ferocious predators. They kill and eat almost everything they meet up with. Insects. Spiders. Lizards. Snakes. Baby mice. Bats. Birds. Friends. Family. If it can be caught, they’re on it, gobbling up as much as they can in their short lives (estimated at only about a year or two maximum). They are the baddest motherfuckers to scan the seas of sand, but unlike what the urban legends purport, their sphere of terror is limited to the realm of the diminutive.
Despite the impressive role they play as tenacious predators in their ecosystem, we don’t really know much about them compared to other arachnid groups. Hopefully, in years’ time, more people will know of solifugids for their very real, very fascinating biology, and not relegate the order to the isolation of limited inquiry, superstition, and misunderstanding.


Image credits: Intro image, scorpion vs solifugid illustration, original for Forever Alone solifugidchelicera close-up, solifugid threat display, pale solifugid with large prosoma, malleoli, solifugid on road, ending solifugid

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Arachnids: Harvestmen

This post is the fourth in an ongoing series on arachnids. Previously, this series addressed whipspiders, hooded tickspiders, and pseudoscorpions. Additional posts on other weird, often overlooked or neglected groups of these creepy crawlies to follow. For a related chelicerate, but as far as science can tell, not an arachnid, see the post on sea spiders.

The harvestman.

In the U.S., Canada, and the U.K. they are generally referred to as “daddy longlegs.” Less often, they are given the name “shepherd spiders”…not because of an adoration of our wooly, farm animal friends, but because their conspicuously long, spindly legs are reminiscent of how, back in the day in Europe, shepherds used stilts to get a better vantage point for watching their flocks…because in those times, people used tools at their jobs that are, today, relegated for the “circus arts” or whatever the fuck the Oregon Country Fair is.

More often than not, we tend to encounter harvestmen in relatively unflattering settings (dusty corners of garages or sheds, beneath untended vegetative landscaping, suburbia in general) and doing unflattering things, like clumsily wobbling off in a direction very loosely resembling “away” from you, teetering along like an intoxicated pre-teen who grew too fast for their coordination to catch up. Within the scope of our lives, harvestmen are no more than the arachnids of unswept places, with vaguely unsettling, Slender Man-like proportions. However, these thread-legged critters are far more interesting and diverse than most of us are aware of, and make up a unique group of arachnids that is regrettably seen as only a curious afterthought amid the dust bunnies and the nooks and crannies of exposed building foundations.

Before addressing these awesome little nuances of harvestman biology, it’s perhaps helpful to get something out of the way: what harvestmen ARE and what harvestmen ARE NOT.

The most important thing to understand from the get-go is that harvestmen are not spiders. They may have the eight, long legs, the roughly circular body suspended in the middle, and overall size and appearance one would associate with spiders, but harvestmen are a different beast altogether. Sometimes, in nature, something that looks like a duck, walks like a duck, and quacks like a duck…is actually a chicken in a Daffy Duck costume. Harvestmen are spiders in the same way that Senator Mitch McConnell is a Galapagos tortoise…through a superficial, yet striking, exterior resemblance and nothing more.

Harvestmen are arachnids that belong to entirely different order from spiders; they are members of the Opiliones (which comes from “opilio”, which in Latin means “shepherd”) rather than the spider order of Araneae. Not only are they in separate taxonomic groups, these groups aren’t even particularly closely related to one another. The order Opiliones is thought to be closely allied with the groupings comprising the scorpions and their closest relatives (like pseudoscorpions and the so-called “camel spiders”), together forming a subclass of arachnids known as the Dromopoda. Generally speaking, a precursory examination of these little guys can lead someone to see the most obvious differences between harvestmen and spiders; harvestmen have body segments fused at a broad juncture into a bean-shaped structure covered in folds of exoskeletal armor, whereas spiders have two easily-defined segments (or “tagmata”)…harvestmen also have a pair of tiny, simple eyes on top surface of the center of their body, while spiders have an array of different types of eyes all at the front of their head region (the “cephalothorax”).

If you are at all familiar with harvestmen (especially if you grew up in the United States) you are almost assuredly acquainted with a frustratingly commonly shared bit of jarringly dramatic “natural history” about their supposed venomous bites. The meme is typically thrown around on playgrounds, where harvestmen are frequently encountered in the warmer months, between children, who relay the idea that harvestmen are “the most venomous animals on the planet” but have mouths and/or fangs too small to adequately pierce human skin, so are of no danger.

This claim sits about as far from reality as you can get. Harvestmen do not only produce not a single drop of venom, they also don’t possess the mouthparts (fangs) that would allow them to envenomate anything anyways. Unlike spiders, harvestmen chelicerae (the appendages in Chelicerates like arachnids that loosely form the mouthparts used to apprehend, dispatch, and process prey items) are segmented and end in minuscule pincers instead of giant, hollow spears anchored to a swollen venom gland. These mouthparts are used to delicately carve up food, like a pair of blunt embroidery scissors, into pieces small enough to fit into their mouth hole. Harvestmen “bites”, when they rarely occur, are more “pinches” than anything else, and are about as deadly as a lick from a puppy.

Harvestmen are perfectly capable arachnids in their own, humble way, not the powerful killers of urban legend, plagued by impotence.

“Sleeping too much? Trouble catching prey, or satisfying your mate? You don’t need to suffer in shame. Ask your doctor about ChelicaMax. Feel like a harvestMAN again.”

If there are any arachnologists reading this right now, I expect there are some chuckles arising at the irony of my cheap erectile dysfunction jab at harvestmen. You see, if there’s any arachnid that doesn’t deserve to be associated with…er…”underwhelming” expressions of manhood, it’s those tall drinks of water found in the Opiliones. Male harvestmen are unique among arachnids because they are the only arachnids to possess a penis. Most arachnids make sweet, creepy-crawly love to one another using “indirect” copulation, which involves the coordinated transfer of a kind of “sperm packet” into a pore in the body of the female…which is less like familiar, human-style sex and more like plugging a tailpipe with a snowball. Harvestmen get down in the “direct” way, with funny looking interlocking components and everything. And by saying harvestmen penises are “funny looking” I mean they look absolutely fucking terrifying. Decorated with a complex assortment of spines, loops, and tendrils, harvestmen dongs look more like something that would slither out of slimy egg sac and slowly kill off B-list actors interstellar, spaceship-bound explorers than…you know…genitalia. For an animal that has legs that are about as flimsy as a human hair, it certainly packs a disconcertingly authoritative member.

Suddenly, the “daddy” in “daddy longlegs” makes me far more uncomfortable than it used to Credit: Sue Lindsay, Australian Museum

Yes, the arachnid that looks like nothing more than long pieces of dried grass stuck to a booger has a dick shaped like an angry, strike-ready cobra.

In addition to this, some species of harvestmen are actually parthenogenetic, meaning that the entire species is female, and reproduces without fertilization from a male (that’s right, some species of “daddy longlegs” have no actual daddies to speak of)…and with males running around with serpent doom-Johnsons primed and loaded, I can’t blame the ladies for going solo.

But of course, for the harvestmen…er…men (I’m a fan of shortening that to “harvestbros”), their pelvic thrust is far worse than their bite. I mean that in regards to their purely mythical venom, and to the unusual way in which harvestmen feed themselves in the first place. To you, me, and anyone other than Charles Bukowski, an entirely liquid diet seems like an odd venture to indulge in. Yet, it is how all arachnids ingest their food; spiders liquefy the insides of their prey with their slurry of digestive enzymes pumped through their fangs, slurping the juicy mixture back in the same way…scorpions dribble digestive goo Brundlefly-style all over their lunch, then suck up the resulting puree of tissue afterwards. Mites feed on liquefied plant cells or animal skin cells. Ticks gorge themselves into red, ballooning, gluttonous oblivion on blood. But harvestmen alone among their arachnid kin feed on the tough stuff, solid food, cutting up pieces of whatever they can find, be it an insect, small frog or other vertebrate, or even a mushroom, and immediately placing it into their digestive tract. This menu by itself is incredible, considering that all other arachnids are either predatory or parasitic, and harvestmen have a varied diet largely encompassing scavenged material from the dead, dung, and plants and fungi. You might think that in the land of the baby food-eaters, the steak-eater is king, but dining on solid pieces of food make harvestmen more susceptible to infection with a number of internal parasites and pathogens (most of these being intestinal nematode worms and pathogenic fungi, both of which can strike their hosts dead) that other arachnids don’t have to deal with, as their liquid, pre-digested diet screens out a lot of these organisms.

Diseased or not, anything that eats hornets is automatically a friend to me.

Harvestmen can bumble through this world alone if they so wish, but many species are very comfortable associating closely with other members of their species, sometimes in large numbers. Harvestmen can congregate in great, dense balls, typically in some protected location near water. In temperate latitudes, this most often occurs with the cool, autumnal approach of the winter months, aligning with the time of the agricultural harvest (hence the common name “harvestman”). Some of these aggregations can reach unreal sizes (reportedly in the tens of thousands of individuals), blanketing rock overhangs or tree trunks, looking like a particularly unkempt patch of pubic hair…that is, until it is disturbed, leading to an exodus of very confused little stick figure fuckers all over the place. Observe the video below, which showcases these living, colonial shag carpets and a pure, uncut hit of the heebie jeebies:

So, you might be saying to yourself, harvestmen a) don’t have venomous bites, b) eat a balanced diet like their mommas taught them to and c) cuddle together in great, shudder-inducing mats, making them easy targets for birds or other predators to shit themselves in excitement and coat their insides with the biggest buffet in their truncated little lifespans….why again are these goody two-shoes, with their apparent lack of defenses, not extinct? Not only are they not extinct, there are 6,500 species currently recognized in the Opiliones, and it’s likely that this only describes half of the actual diversity of harvestmen on Earth. They are a very old and successful group of arachnids, stretching back well over 400 million years, and they appear to have changed jack shit about their biology in that period of time; fossilized species dating back more than 100 million years before the first dinosaurs are barely distinguishable from modern harvestmen. So what’s their secret to even the most limited level of survival in the brutal, roiling pot of nature, where everything is trying to eat everything else, poop it out….and then eat it all over again?

For one, harvestmen have a few behavioral tricks up their long, long sleeves. Some species, when encountering a predator, sway their bodies erratically on their wiry legs. This bit of unpredictable movement is, understandably, unnerving, and often the predator is too befuddled to attempt messing with the dancing harvestman. Many species also engage in “autotomy”, which is where an animal sheds an entire body part, like a limb or a tail (as in many lizard species) in order to distract a predator, allowing for a quick getaway. In autotomous harvestmen, the gangly legs are what are cast aside in a pinch; at the junction of the “hip” the limb is severed, and the harvestman wobbles away as fast as the remaining seven legs can take it. This strategy’s effectiveness is boosted by another unique feature of harvestman biology; their respiratory system. Unlike most other arachnid groups, harvestmen don’t have book lungs, the folded structures that perform gas exchange in spiders, scorpions, etc., but instead breathe through small holes and tunnels running in and out of their exoskeleton; tracheae. Many have spiracles (holes) that allow for air to enter on each of the legs. If one of these legs is kicked to the curb in a permanent sense, it still retains a small part of the respiratory system. In many autotomous animals, the lost body part thrashes and twitches violently for a short while to keep the attacking predator’s attention long enough for the escape to be a success. The harvestman’s leg continues to draw oxygen into all of the tissues of the limb for a great while after being disconnected from the body, nourishing excited nerve fibers with fresh oxygen, and letting the disembodied limb, ala the Addam’s Family’s “Thing”, move around, deceivingly, for many minutes later.

Despite a slight shot to their over-land fleetness (and maybe a case of phantom limb syndrome or two), harvestmen seem to use this anti-predator strategy frequently (many harvestmen are found with seven or fewer legs), competently temporarily evading death by means of the world’s most gruesome take on the Hokey Pokey.

“Self-amputation is what it’s all about, kids.”

Another defensive measure commonly used is a little less subtle. Rather than stupefying with killer dance moves, or putting on a literal, live rendition of My Left Foot, harvestmen can also turn themselves into a meal that spurs on acute contrition for the unwary diner. Most harvestmen have specialized glands, called ozopores, located at the sides of the front of the “head” region (called the cephalothorax in many arachnids, the “prosoma” in harvestmen). These glands, derived from simple scent glands, secrete a rank fluid concoction that is repellent to both the nostrils and the taste buds. When compressed or harassed, the harvestman squeezes the noxious fluid out of the sides of its body with muscular contractions, and the chemical blend presents itself as milky droplets seeping out behind the folded chelicerae.

“I come from a long line of longleg milkers. It’s a dying art.”

Modified from Chemical defense of an Opilionid (Acanthopachylus aculeatus) . Thomas Eisner, Carmen Rossini, Andres Gonzalez and Maria Eisner . 2004. Journal of Experimental Biology 207, pp. 1313-1321.

A major chemical component of these secretions is benzoquinone, a toxic compound that smells like heated or melting plastic, mixed with an over-chlorinated swimming pool, and if it gets pretty much anywhere on you, the effects are fucking nasty, interfering with oxygen transport if ingested (along with lots of weakness and vomiting) and irritating the sensitive membranes of the mouth and nose, blistering exposed skin and eyes. The overall effects of the chemical secretions, and their effectiveness as deterrents vary significantly between species of predator, as well as the species of harvestmen, as the makeup of these poisonous cocktails differ enough between groups of harvestmen that they can be highly informative when it comes to identifying species, or classifying newly discovered ones.

All of these weird traits, the purposeful loss of legs, the caustic armpit drippings, the shoulder-to-shoulder-to-seven-other-shoulders congregations of a number of individuals that exceeds the maximum capacity of most Division I football stadiums, are all well and good, but harvestmen aren’t exactly the most interesting things to look like. All of them have the same, simple construction; spindly legs, nondescript, oval-shaped body, tiny eyes, and barely discernible chelicerae. Even the most colossal species of harvestman, with legs so long it could hug a throw pillow, looks the exact fucking same. More or less, they all look like a spider sketched by an artistically-challenged 3-year old. Little ball, lots of long, skinny sticks attached.

Right? Wrong.

Most of the harvestmen encountered by folks living in the temperate Northern Hemisphere and greater Anglophonic world (also the major audience of this blog; don’t worry, I check my visitor stats, I’m very aware most of ya’ll are from the West) appear this way. Most of these species also belong to a single sub-order of Opiliones, the Eupnoi, which contains about a fourth of all described species of harvestman. However, the bulk of harvestman biodiversity is situated in the sub-order Laniatores, with about 4,000 species. These harvestmen, which have their highest numbers in the humid forests and caves of the subtropics and tropics (particularly in South America), tend to look very different from their European and U.S. cousins. Many species have thick-plated body armor, surreal proportions, nefarious-looking thorns and projections, and….well…you’ll see what I mean if you just look…

This adorable little bucket of terror is Soerensenella prehensor, native to New Zealand. It’s a member of the Triaenonychidae family of harvestmen, which are found chiefly in North and South America, Madagascar, Japan, and Australasia. They are characterized by their relatively short legs, and grotesquely expanded pedipalps which resemble a pair of ice cream scoopers that someone covered with crazy glue and dunked in a dish of thumb tacks. It’s thought that these crampon-lined bear-huggers are used in the same fashion as the lightning-fast, weaponized front legs of a praying mantis; to ambush and spear prey, bringing it close to those hungry mouthparts, effectively impaled into submission by a thorny embrace.

Oh, what now? A Headcrab with rickets?

Some tropical Lanitorian species of harvestmen look like the Pokemon “evolutions” of smaller, scrawnier versions of the arachnids. An example of this is the hulked out, walking Dali painting above, Pachyloidellus goliath, and it is found in high-altitude areas in Argentina. The swollen body and studded armor plating might be intimidating, but it has more renown due to its particularly odoriferous ozopore secretions. The smell is apparently so repulsively offensive, that in the local Quechua language, it is called “chichina”, which is in loose reference to another endemic arthropod that defends itself with a stinky discharge, a relative of stick insects (Agathemera crassa) which is called “chinche molle.”

There are alien-looking harvestmen outside of the Laniatores as well. Some are nested right within the supposedly “familiar” Eupnoi group. For example, there’s the harvestmen of the genus Megalopsalis found in New Zealand, which have males with outlandishly overgrown, 2-segmented chelicerae that they keep tightly folded up like a pair of butterfly knives during most of their day.

“All the better to creep you out with, my dear.”

Chelicerae among females are pretty standard, so, although not much is known about these guys, it’s likely the ridiculously giant mouthparts have some history in sexual selection. They could be for male-male competition, in the same vein as bull elk that clack antlers together. Or it may be directly tied to female mate choice, where no fighting is involved, but the males showing off the most preposterous chelicerae (or rather, the males healthy enough to grow and maintain such cumbersome body parts) are scored as a particularly good date and/or father of many multitudes of larval children.

Finally, there are some members of the sub-order Dyspnoi that deserve mentioning, a small group of less than 400 species of harvestman found only in the cool latitudes of the Northern Hemisphere and are thought to be closely related to the Eupnoi cluster of species. One species of harvestman within the Dyspnoi is a shining-star example of the evolution of weird dietary specialization. It is Ischyropsalis hellwigi, native to central Europe, and it eats snails and other molluscs (scientists think exclusively so). If you are wondering how it manages to do so, seeing as how snails have protective shells (kind of a big part of being a goddamn snail) and how typical harvestmen have the kiddy scissor version of chelicerae, and even the elongated examples I pointed out above don’t seem to have any real power behind them…might as well try to crack a coconut with a back-scratcher….you’d be correct to be skeptical. Luckily, both sexes of I. hellwigi look like they’ve been taking syringes of nandrolone in the ass for years on end, and are gifted with the some of the planet’s most ‘roided out harvestman chelicerae, period.

Schwarzenegger up there has a taste for escargot, and those lobster-like claws, bulging with muscle inside their exoskeletal prison, are the perfect tools for the job. There hasn’t been really any record of these harvestmen eating snails in the wild, but that might be more due to the fact that they are very much nocturnal and aren’t exactly common…so stumbling across one of these arachnids isn’t likely in the first place, let alone one in the middle of a meal. In captivity, however, these wanna-be prawns go ape shit over being introduced to snails and slugs, which they dispatch immediately with a cold, calculated method of deconstructing the snail’s happy little mobile home. It apparently involves propping the shell up with one powerful chelicera, and then chipping off fragments of shell with the other claw, incrementally whittling down to the prize at the core, like the world’s most patient consumer of a fortune cookie. Eventually, the mollusk’s soft body is reached, ripped through the harvestman-carved window in the shell, and greedily devoured. These harvestmen are also known to take down slugs and snails multiple times their mass, because these are apparently arachnids with not even the faintest trace of a fuck to give.

Whether they are bobbing their way out of getting wolfed down by a lizard, clambering over the forest floor 400 million years ago, or looking like warty alien spiders that stepped right out of an Avatar rendering, harvestmen represent an amazing and diverse order of arachnids. Perhaps most exciting? We still know almost nothing about the huge numbers of opilioids that have been discovered, particularly the bizarre forms that hide quietly in the equatorial rainforests. We are only now starting to understand the chemical composition of their defensive ozopore secretions, and seeing as how there is an unusual level of variation between families of harvestman on what types of compounds are produced, and a high number of active products (sometimes nearing 100 or so compounds), there is a plenty of opportunity to discover chemical compounds that, if co-opted and adapted, might serve humankind well in the areas of medicine or industry.

Image credits: Intro harvestman, harvestman closeup in grass, harvestman with hornet abdomen, harvestman with white background, Sorensenella, Pachyloidellus, Megalopsalis.

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Armed to the Teeth: Bites from Forgotten Sharks

As the 31-day stretch of August rapidly rushes to completion, and the balmiest days of summer fade into the imminent, cool veil of fall, 2014 also discards one of its temporal landmarks associated with these heat-stricken days. If you think I am referencing something remotely anapestic and evoking chest-fluttering nostalgia of long-forgotten, canicular childhood summers, then think again. Because I am, of course, talking about Shark Week.

Yes, that now-legendary bit of the Discovery Channel’s summer programming line-up, a selachimorph-centered festival that is closing in on three decades running, has now passed us by, ending but two weeks ago. Years ago, Shark Week initially appeared to be driven with the mission statement of Discovery in mind, one rooted in the dissemination of fundamentally educational, science-based material in an entertaining manner. This incarnation of Shark Week was the one I was fortunate enough to grow up with, and this week was a boon to my insatiably science-curious child brain, one that my neurons practically salivated over in Pavlovian form right around the time the last traces of abandoned, burnt out firecrackers left July’s dirt. The gift of science education excellence was instrumental in the development of my eventual fascination (and career trajectory) with biology, and I credit the old-school Discovery Channel’s programming with much of the inspiration and intrigue about the natural world that gilded my early days.

At the age of four, my shark ID skills were solid. However, my artistic skills were still…er….buffering.

So, given the intimate intellectual relationship I have with Shark Week and Discovery, watching what both entities have become in recent years feels like a steel-toed kick to the kidneys. There are a laundry list of offenses, and all of them hit on a single formula; the sacrifice of ethics and scientific accuracy in favor of mythology and adrenal-gland massaging codswallop; a grand invasion of heart-pumping, flash and sparkle nonsense programming based on approximately zero micrograms of actual science, all as an ill-conceived motion to inflate ratings. Some examples of Shark Week contrived falsehoods? Well, there’s this lovely bit of mass hysteria-inducing, publicity-hungry deceit initiated by cries of “oh no! Lake sharks! *wink wink*.” Also, there’s that time Discovery trotted out this steaming, embarrassingly unscientific pile of horseshit. Oh, there’s also that other time they made an entire special up. Or how about how the network can only seem to convince scientists to do Shark Week specials with them if they straight-up con them into doing so?

Others (linked above) have done a splendid job of calling out the network’s recent, fraudulent Shark Week habits, so this post isn’t going to be yet another dart in that already well-pockmarked board, but what I want to address is loosely tied to Shark Week’s newfound adoration of Megalodon (well, specifically an adoration of tricking viewers into believing the very extinct shark is still patrolling the deep…now for two years in a row).

“Megalodon”, or to be more accurate Carcharocles megalodon (or Carcharodon megalodon, it depends on what paleontologist you ask) is a popular beast, and thus is an obvious choice for many an examination by television networks (in mockumentaries or not). The extinct shark species is popular for damn good reason, too. C. megalodon was an animal of such outlandish proportions that it doesn’t seem like it could ever have existed, and yet it did, for more than 26 million years, dying out right around the time our ancestral line first harnessed that hot, orange, light-producing stuff that eats up wood (followed swiftly by the invention of S’mores and crappy ghost stories). This was a shark that, according to the most conservative estimates, exceeded 45 feet in length, and had a pair of cartilaginous bear trap-esque chompers big enough to gulp down a Ford Fiesta without even scratching the paint on its immense, triangular teeth.

And oh yes, those teeth. Those frisbee-sized blades that festooned its jaws in a ragged chain of despair. Those famous teeth, for which the animal is named (megalodon basically means “giant fucking tooth”), combined with a body bigger than a goddamn school bus, have enraptured the imaginations of young and old alike, and contemplation about what it would be like to encounter such a surreal, monstrous animal in the flesh is unavoidable.

But, here’s the deal with ol’ Megs…outside of its status as by far the largest shark that ever lived, and definitely one of the biggest predators to ever exist (getting edged out by the sperm whales alive today)…as far as we can tell, there’s nothing insanely unique about its biology. Granted, one of the most fascinating things about C. megalodon is that we don’t know that much about it. Even the size of the thing is sort of up in the air, seeing as how the scientific community has only fragmentary remains (teeth and a handful of vertebrae; the cartilaginous skeletons of sharks don’t fossilize as readily as bony skeletons, so this dearth of recorded remains is not that unusual) from which to base their calculations; estimations range from the 40s of feet in length to more than 60 feet…which in my book is the difference between “we’re going to need a bigger boat” huge and “I’m going to need a new pair of pants” huge.

Honestly, C. megalodon was cool and all, but it was basically just a Hulked-out version of any large lamniform shark (Lamniformes being the order of sharks to which great whites and makos belong). The animal is more or less like a great white had a run in with Rick Moranis and his growth ray, with maybe some very subtle differences in proportions…and a slightly different taste in prey…like taking on goddamned whales instead of comparatively diminutive sea lions. Yes, C. megalodon was something of a specialized whale killer…a shark exquisitely well-adapted to slaughtering and consuming the most massive animals of all time.

So sure, it’s teeth were heart-stoppingly big, and robust, and belonged in the titanic jaws of a beast of celebrity status….but they were just relatively standard lamniform teeth ratcheted up in size, with some limited modifications for slicing through several hundred cubic feet of whale flesh and bone at a time (increased thickness and bigger, deeper roots). For an animal so well-known for its mouth, it certainly didn’t have the most unique pearly whites among extinct sharks. The diversity of prehistoric sharks, and the diversity their feeding adaptations (which often are very divergent from today’s sharks), are woefully unappreciated, at least in comparison to C. megalodon, which is a remarkable shark due to its size and power…but I can think of a couple examples of long-extinct sharks that have far more interesting things going on at their eating ends.

Take Cretoxyrhina mantelli, for example, pictured below in this reconstruction by paleo-artist Dmitry Bogdanov, which given this speculative coloration, appears to be a shark that has deceptively splashed its belly in paint in a desperate attempt to mimic a great white shark.

I blame unrealistic standards of shark intimidation in the media.

Cretoxyrhina wouldn’t have had to try too hard to look like the most powerful predatory shark of today’s oceans (the great white), considering that they were very close relatives and reached similar sizes (although Cretoxyrhina likely got even larger, topping out at around 23 feet (7 meters) or more in length). Cretoxyrhina was a member of the same taxonomic order of sharks that great whites and C. megalodon belonged; Lamniformes, a group of sharks characterized by relatively conical snouts, five gill slits, and a mouth that sits behind the eyes. Cretoxyrhina was part of different family of sharks than today’s sea lion tossers, but they were more or less cut from the same evolutionary mold.

Cretoxyrhina patrolled global shallow seas between about 80 and 100 million years ago, meaning that it was separated from the most ancient great white sharks by the same immense length of time that modern humans are separated from the last of the dinosaurs. One of the places it called home, and where many high-quality fossil remains have been discovered, was Kansas. Cretoxyrhina didn’t frequent the Sunflower State because it craved barbecue and pursued the smells wafting out of Kansas City by crawling through wheat fields Land Shark style. Cretoxyrhina has fossils coming up in the heartlandiest part of America’s heartland because during the Mid-Cretaceous era, this entire region was covered by the Western Interior Seaway, a great swath of saltwater that divided North America longitudinally into two giant landmasses, running unbroken from the Gulf of Mexico to the Arctic Ocean. The notion that Kansas, and much of the American Mid-West, was a sea bed tens of millions of years ago isn’t that surprising considering that the region is flatter than twenty year-old can of Crystal Pepsi. It’s flatter than Bernie Lomax’s ECG. Flatter than that dusty, unused piano in your grandmother’s guest room. Flatter than how a joke about twerking falls at an AARP convention. What I’m trying to say is that Kansas is flatter than shit (and honestly, it’s kind of a dull, featureless, oppressive shithole, both due to the aggressive summer heat and the legions of hyperreligious, bug-fuck insane, freedom-fried inhabitants…sorry Kansans).

The Western Interior Seaway was an ocean that teemed with a rich diversity of marine life, and provided Cretoxyrhina with a smorgasbord of flavorful, finned fauna upon which to dine…and dine it did, with a set of some of the most impressive teeth to evolve in the hundreds of millions of years of shark prehistory. These knife-like teeth, some two inches long and numbering more than thirty in each jaw not counting the replacement teeth “on deck” (compared to the twenty-five or so in great white jaws), are graced with a unique characteristic of their construction; the presence of an unusually thick, resilient enameloid (similar to enamel, the hardest, outermost covering of human teeth) coating. These teeth had the impeccable sharpness common to predatory sharks in general, combined with an unprecedented toughness. Cretoxyrhina was equipped with teeth that were particularly good at biting into very hard, bony or shelled things over and over again, and successfully cutting them into manageable, bloody chunks. For this reason, Cretoxyrhina is commonly called the “Ginsu shark”, referring to the famous, supposedly exceptionally sharp cutlery hard sold via infomercial in the 70s and 80s.

It’s perhaps incredibly fortunate for Cretoxyrhina that it had this buzzsaw of a mouth at its disposal. The Mid-Cretaceous oceans, especially in the bountiful, warm, shallow waters of the Western Interior Seaway, were full of “difficult” prey items and “worrisome” predator competition…and by “difficult” and “worrisome” I mean that they would make today’s most effective and brutal marine predators jettison the contents of their bowels into the water column in a fit of terror. Middle America some 90 million years ago was a lukewarm cauldron full of an assemblage of aquatic monstrosities that appear to be lifted straight from the sketchbook of a deranged 8-year old child. Among them was Xiphactinus, a voracious, needle-toothed fish with a dramatic, bulldog-like under-bite and a body the size of a Chevy Tahoe. There were also plesiosaurs like Elasmosaurus, whale-sized, snake-necked reptiles that look more like something hunting in the subterranean oceans of Naboo than something that actually existed on Earth at one time. The seaway also was home to sea turtles that weighed more than two tons, and a number of mosasaurs like TylosaurusFor those unfamiliar, mosasaurs were a group of marine lizards that reached their heyday at the tail end of the Cretaceous, and were basically a hellish amalgamation of crocodiles, eels, and sharks…but blown up to the size of an orca. Wherever mosasaurs swam, they, understandably, were among the most dominant predators in their ecosystem. Similar throngs of animals were found in epicontinental seas (inland seas and seaways) and continental shelves (areas offshore where the continental plate is submerged in the sea; more shallow than the middle of the oceans), prime Cretoxyrhina habitat, the world over.

The “Ginsu shark” may have been an impressive fish, with its gob full of diamond-tipped blades and imposing bulk, but it was just one of many giant predators in the tepid Cretaceous oceans.

So, there was a glut of flesh, bone, and teeth during this time; on land there were still the big, non-avian (non-bird) dinosaurs, and in the seas, gigantic reptiles and fish. Cretoxyrhina was likely superbly adapted to exploiting food sources in these treacherous waters via its uniquely effective bite. Flourishing in a sea full of big, armored, active animals means you have to have the capacity to take a shot at just about anything…and it appears as though Cretoxyrhina did just that. Cretoxyrhina teeth and bite marks are found in just about every big animal it shared the water with; Archelon, the largest sea turtle to have ever existed, got jacked up by this shark…the shark tore into giant pleisosaurs….and even went after the biggest and least-fuck-withable things around, mosasaurs. It is often hard to tell from the fossil evidence whether or not affixed teeth or scarring on bone is the result from an actual attack and feeding, or simple posthumous scavenging. However, there are examples in the fossil record of Cretoxyrhina making a failed attempt at a kill of a mosasaur, evidenced by the mosasaur’s vertebrae having shark teeth embedded within the bone, where the injury became infected, subsequently healed, with the bone growing over the tooth like a tree trunk slowly enveloping a fence over decades. Think about that for a second; mosasaurs, a predator group so heinous that it likely had an impact on the decline of entire orders of other humongous, fang-toothed, marine reptiles like pliosaurs and ichthyosaurs, were a menu item for Cretoxyrhina. Even if most of its interactions with the largest predators and prey in the ocean were, realistically, opportunistic events where it fed on small, young, or sick individuals, or just devoured the dead…the Ginsu shark assuredly occasionally used those incredible teeth against things that were very big, very strong, and very dangerous.

Cretoxyrhina wasn’t the baddest bastard under the waves, but outfitted with a bite that could cleave several inches of bone in an exposed mosasaur flipper as effortlessly as a light saber carving through a gelatin salad, it sure as shit acted like it was. C. megalodon may have chiefly fed on giant whales…but baleen whales don’t have the ability to fucking bite back, and for that reason, Cretoxyrhina’s comparably courageous habit of recklessly targeting actual, real life sea monsters as food, as if it’s filming an episode of Jackass, receives an award for Heftiest Gonads of Shark Prehistory, at least in my book.

A second shark with a special set of teeth actually lived in the Western Interior Seaway during the same era as Cretoxyrhina, but this shark fed itself in a way not often associated with anything vaguely related to the common conceptualization of how a “shark” is supposed to make a living. A major part of this reason is because this shark had teeth that looked very similar to these:

Less with the “serrated death dagger” and more with the “wrinkly elbow” look

These teeth belong to a species of shark in the genus Ptychodus. Ptychodus was one of the last remaining examples of a group of sharks known as hybodonts (order Hybodontiformes). Hybodonts evolved more than 300 million years ago, and were incredibly common throughout the “age of the dinosaurs”, but eventually were out-competed by more sophisticated, less primitive sharks and died out sometime near the end of the Cretaceous. At the very end of their time on Earth, some bizarre, specialized forms had evolved, and Ptychodus was one of them.

Ptychodus had a set of jaws packed with rows of flat, bottle cap-shaped teeth arranged in a dense formation that resulted in a functional “plate” in both upper and lower jaws, opposing each other. This meant that Ptychodus obviously had a vastly different dental set up compared to other contemporary sharks, with much of the jaw toothless, save for this odd battery of bumpy hubcaps crammed together at the very front of the face.

It also meant that it had jaws that weirdly resembled the human female reproductive system.

It is thought that these mouths full of molars were an adaptation to feeding upon a very specific, and very locally abundant quarry; shelled animals, particularly clams. This type of feeding on tough, hard-shelled organisms, involving using broad teeth and powerful jaws to crush the shell outright, is known as “durophagy”, and outside of the limited number of species of bullhead sharks, it is not a strategy employed by modern sharks. We don’t know a whole lot about what they looked like and how they behaved, but given what we know about living sharks that have slow-moving prey that stay close to the bottom, we can surmise that Ptychodus had similar characteristics, in that it was likely slow-swimming (since hunting clams and urchins and other spiny, shelled critters doesn’t exactly require much chase) and resembled sharks with similar habits, like a nurse shark, for example.

This dietary specialization is unique, but one species of Ptychodus, Ptychodus mortoni, unearthed in Kansas several years ago, takes the entire game to a whole other level by being huge, based on calculations from fragmentary remains. How huge? Ten meters huge. That’s longer than a lot of sailing yachts.

P. mortoni was among one of the largest sharks of all time (and certainly one of the largest durophagous creatures of all time), and if it were alive today, it would only be exceeded in mass by whale sharks and the occasional basking shark…so it must have been eating bucket loads of clams to sustain itself, right? Not necessarily, at least not the types of clams you and I are familiar with. The Western Interior Seaway was also inhabited by a giant organism of a different stripe; Platyceramusthe most titanic genus of clam to ever sit, boringly, in the loose silt at the bottom of the sea. It was a clam with a shell that, at its smallest was bigger than your bulkiest, most airline-unfriendly piece of luggage, and at its largest, could fill an entire living room. A single individual could produce enough clam chowder to quell the hunger of a hundred famished New Englanders. Platyceramus was so insanely colossal that it served as a micro-ecosystem in and of itself, being utilized as protection for scores of fish, as well as a substrate for other shelled animals to attach and grow. This mega-mollusk, which makes the giant clams of today look like dinky, littleneck clams, was likely splintered by the insatiable car compactor jaws of P. mortoni, and the great underwater fields and reefs of these clams that once lined the shores running up and down the soon-to-be Great Plains could have been a major source of food for such a giant fish.

It’s unknown exactly what brought an end to P. mortoni. During the latter part of the Cretaceous, hybodont sharks were being outpaced by “newer models” of sharks, generally speaking, but given P. mortoni’s level of dietary specialization, traumatic ecological competition doesn’t seem too likely, unless some other giant durophagous fish rears its head in the Kansan fossil record. It’s also unclear if this shark was a victim of the same extinction event that leveled the non-avian dinosaurs, marine reptiles, and pterosaurs. A third route for its extinction might be linked to its selective diet, and the fact that, as of right now, has never been found outside of the range of the Western Interior Seaway. The seaway eventually closed as the Cretaceous transitioned into the Paleocene, and with it went all the habitat that made such rich grounds for an endless supply of outsized clams. It is possible that even if this last holdout of the hybodont family line managed to slip past millions of years of competition and an abrupt, catastrophic, global extinction event…it could have fallen victim to the incredibly common ecological and evolutionary phenomenon of being exceptionally good at a far too few number of jobs; the biggest species of Ptychodus did a wonderful job of scooting along the bottom of the ocean, shattering clam beds like a steamroller making its way through a ceramics class…but once the clams are gone, unemployment hits swiftly. Unfortunately, ecological unemployment tends to be irreparable, and fatal.

Either way, much like the limelight awash C. megalodon, both these other noteworthy sharks and their astonishing bites are forever lost to the lonely, backward expanse of time. It’s been many tens of millions of years since Cretoxyrhina last unwisely harassed the most decidedly inedible animals to ever evolve on this planet. Ptychodus hasn’t lazily busted open a couch-sized clam in almost that long. No modern human has ever had the undoubtedly epic experience of seeing these three animals alive, and barring the eventual invention of time travel, no human ever will. These animals, along with their incredible teeth, feeding behaviors, and overall biology, are quite dead.

We should consider ourselves lucky that a diversity of groups of sharks made it out of the Mesozoic era and arrived at the present day, continuing their several hundreds of millions of years of existence in our oceans. Multiple lineages of sharks today depart from the archetypal “tooth torpedo” form many of us have assigned to sharks, and engage in a wide array of unique feeding strategies. Unfortunately, many of these sharks are also threatened with extinction. Some hammerhead sharks use their hammer-shaped cephalofoil, armed with a high density of electroreceptive sensors, like a finely tuned metal detector, searching for the slightest signs of stingrays partially buried in the sediment at the bottom of the sea, which are then pinned down in a flash of cartilage-on-cartilage savagery and ingested after being rooted out from their hiding place. These remarkable sharks are also distinctly endangered, with two species currently regarded by the IUCN as endangered, and another as vulnerable. The whale shark, an enigmatic, beautifully serene animal that feeds entirely on plankton via filter feeding in a very unstereotypical fashion (for a shark), equipped with a mouth shaped like an envelope slot and with its closest relatives consisting of tiny, bottom-dwelling, camouflage-embracing sharks, is also the world’s largest “fish”, growing to more than 40 feet in length. It too is considered to be vulnerable to extinction, with major causes of concern of population decline stemming from fisheries that target the sharks, to habitat loss and depletion of the quality of feeding waters. The river sharks of the genus Glyphis are remarkable solely for the fact that they live completely within freshwater river systems, unlike any living sharks (bull sharks are renowned for their ability to access fresh and brackish water, but these sharks depend on saltwater for reproduction and are therefore not truly freshwater animals). River sharks are so rarely sighted (and as a consequence, so poorly understood) that it’s possible we haven’t identified all members of the group yet, and some of the ones we know about are undoubtedly critically endangered, especially those constricted to heavily polluted and overtaxed river basins in Southeast Asia. Sawfish, while not actually sharks (they are instead rays), grow to very shark-like body sizes and use an amazing, tooth-studded, electrosensor-lined bill to detect and stun/impale prey from its position on the muddy bottoms of lagoons, estuaries, and river deltas. Not a single accepted species of sawfish isn’t immediately endangered with extinction.

It is far too late to observe Cretoxyrhina or Ptychodus, but the exceptional elasmobranchs I listed above are modern. They exist as a part of our present day world, at least for now. Whether or not they begin to fade into the permanence of the fossil record, one by one, is largely up to us.

Image credits: Tooth intro image, Cretoxyrhina, Ptychodus teeth, Ptychodus jaw

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Macabre Moths: The Infernal Nocturnals

My girlfriend is terrified of moths.

She hates them; purely, unabashedly, and completely. She despises their habit of gracelessly barreling out of the dark, smashing into anything and everything (including human faces) in a flurry of fluttering wings. She hates the way they persistently ram themselves into outdoor lights,  which oh-so conveniently tend to be right above her head just outside of the front door, cutting her off from the frustratingly close safety of her house. She loathes the angry drumming sound they make when they clumsily bat their wings against whatever wall or window they are crawling across. She shivers at the mention of their wings, which she describes as “dusty” (the powdery coating is actually made up of very tiny scales that cover the wing; butterflies have these as well). I’ve watched her spot a particularly massive, beastly, mothy bastard spread out sinisterly underneath a neighbor’s outside window sill, and immediately swing her path past it into a wide berth, eyes cautiously locked on the insect threat. She does not like them here or there. She does not like them anywhere. My girlfriend does not like the moth. She does not like them, David Lee Roth.

Because of her undeniably real, demonstrably intense dislike of moths, she was not exactly appreciative of the fact that the last week of July (July 19th through July 27th) was National Moth Week (or of the fact that I’m writing this blog post at all, frankly). For those of you that are unfamiliar, National Moth Week, started in 2011, is a global citizen science effort wherein groups of those inclined (called “moth-ers”, but I like to call them “moth-heads”) set out into the night equipped with lights, a white sheet, a bait mixture made of something like rotten fruit, molasses, or beer (preferably not the good shit; stick to domestic swill like Bud or Coors), and perhaps a camera for recording purposes…all of this to observe and categorize whatever moths they find attracted to their lights or bait, and to potentially contribute their findings to a multitude of databases. In this bit of crowdsourcing of data collection, we are able to know a bit more about the distribution of moth species (and for many species, where they turn up in the world is not well-known), and their general abundance over time, which is important to keep track of, considering that moths are good early indicators of decline in an ecosystem’s ecological health. Another major focus of National Moth Week is to bring awareness to moths, which are oftentimes regarded as boring, drab nuisances instead of the diverse, often colorful, interesting animals that they are. NMW also provides an opportunity to get groups of school age children together to not just learn about moths and the natural world that surrounds where they live, but to take part in a globally held citizen science project, hopefully inspiring some of them to take interest in the biological sciences in a more permanent sense.

Truthfully, moths are far more interesting than we give them credit for. They are diverse in form, size, coloration, and behavior. They are unfortunately pegged as dull creatures, which, at their best, are annoying, and at their worst, a pest that destroys clothes and crops. There’s a single thread runs through their popular characterization; one that paints moths as fundamentally benign, like a house fly, or a slug…something to put up with, and nothing to get too excited about; the “white bread” of the insect world. But, while it’s important to remember that moths are interesting by being incredibly important members of their ecological communities, as insatiable, leaf-obliterating larvae, as pollinators of flowering plants, or as nutrition for everything from birds to bats…there are a number of species that solidly destroy the notion that moths are innocuous at the acutely individual level. Some species are downright threatening, blatantly ignoring the memo about how moths are “supposed” to be the awkward, dirty, night shift butterflies of the world and nothing more disconcerting. These species, twisted, creepy, grotesque, and malicious even by arthropod standards, make it difficult for me or anyone else to dismiss my girlfriend’s mottephobia (the fear of moths) as being unfounded.

First, behold Chionarctia nivea, a superficially normal-looking type of icy white “woolly worm” moth that frequents the frigid northern reaches of Russia and East Asia, where, based on the elegant evening wear it has on in the photo below, it apparently flutters around perpetually dressed like Galadriel.

“I give you the light of Eärendil, our most beloved star. May it be a light for you in dark places, and a place for you to slam your face into over and over again in confusion and blind desperation. “

It’s a nice looking moth. Personally, I dig the sleek, streamlined thing it’s got going for it, and the titanium white coat gives it a classy aesthetic. It lives a very mothy life, doing lots of the typical mothy things. There’s nothing observably alarming or offensive about this species, which conveniently disguises itself as a cottonball, which is perhaps the mascot for unblemished innocence. This is a good, clean moth you can trust. This is a moth that pays its taxes, that always drives 5 mph under the speed limit, and has superb credit. This is a moth who you might feel comfortable voting for in the upcoming school board elections, because this moth has integrity, goddamnit, and integrity is hard to find these days.

But the males of this species conceal a disturbing secret…

With a bit of air pressure, the Chionarctia nivea moth deforms its abdomen into an awful assembly of alien French ticklers, unfurling bits of prickly, translucent membrane into the world’s worst precursors to balloon animals.

So, why? Why do the dude moths in this species insist on extruding these visually comfortable and vaguely threatening ass tentacles, immediately transforming themselves into something that looks like it would terrorize Kurt Russell in an Antarctic research station? And what do these organs do?

If you are asking yourself if the male-specific, extendable, phallic appendages are “a sex thing” then your suspicions are correct. These are totally a sex thing. But these love balloons ain’t for the actual moth hanky-panky. They are instead used in the initial wooing of females of the species. These organs (called “coremata”, and are found in lepidopterans (group of insects that includes moths and butterflies) in general) are lined with bristly structures called “hair-pencils”…and these hair-pencils write the language of sweet, sweet, moth-y love.

Well, to be more specific, they release a cocktail of pheromones that advertise to the female moths that the owner of those sexy coremata is a choice mate. When a male moth gets wind of far-spreading female pheromones, he tracks her down, and once close enough, he puffs up those fuzzy butt feelers like a pair of inflatable, advertisement airdancers and lets loose his intoxicating cologne. If the lovely lady is satisfied by what her antennae are picking up, the two love bugs can commence with the bumpin’ of abdomens. The hair-pencil pheromones also appear to have a repellent effect on other males of the species. Once the stank of another bro moth’s sex solicitation juices are mucking up the air somewhere, it’s a bit of a turn-off to all the other males, apparently.

So, one species’ sickening “I don’t know what it’s doing, but get that fucking thing away from me” is another species’ steamy courtship display.

Alright, you say, so some species of moths have males that are particularly…er…”well-endowed”…with respect to their creepy, pneumatic, romancin’ not-penises. Big deal. It’s not like they are actually doing anything malicious. You are, perhaps understandably, unimpressed with this example of moth malice.

So, I say, consider the following scenario:
It’s a warm, humid night in the outlying, forested areas surrounding Vladivostok, Russia. There’s not much of a breeze tonight running onto shore from the Sea of Japan, and the air is thick. You are sitting out on your porch, drinking a Yarpivo Amber, trying, in vain, to use the night air to cool yourself. The coniferous forest around you is alive with the songs of crickets, and the darkness enveloping you, and the alcohol trickling from your blood and into your brain allow a blanket of relaxation to drape over you. Just before you drift off to sleep, a wayward, winged insect visits your position under the white intensity of your porch light. It’s a nondescript, little brown moth, and it delicately settles all six of its petite feet upon the back of your hand. You’re careful not to move and scare it off as you watch it wander back and forth across your hand, stumbling over the occasional hair, antennae twitching and wings wavering slightly to keep balance. You are instantly calmed by this intimate moment, briefly connecting with nature. An angel of the forest has stopped by and offered you the gift of its presence, and you feel as though the two of you are communicating on some kind of deep, ancient, spiritual level.
Just as a smile begins to illuminate your face, you watch as the moth slowly and deliberately unrolls its long, fragile proboscis…and proceeds to drill the end of it into the skin between your knuckles. Pain and shock jolt you to full, electric alertness as the moth plunges the sharp tip of its tubular tongue into your flesh and greedily laps up your blood like a cat at a water dish.

You’ve just had a run-in with the vampire moth, Calyptra thalictri.

Most adult moths and butterflies are passive nectarivores, and spend their days daintily sipping sugary nectar from wildflowers and flitting about as if their entire lives were an extended, sunny, spring tea party. But not Calyptra, along with its close relatives in a small subfamily of owlet moths (Noctuidae). These guys, much like the mosquitoes and bedbugs were are more familiar with, are hematophagous, meaning that they feed upon blood. Calyptra is a branch of the moth family tree (native to much of southern Europe, Asia, and sub-Saharan Africa) that has taken a hard, evolutionary turn away from an existence dipping into daisies, and has made a serious of concerning, demented life and dietary decisions that would surely put a smile on the face of Bram Stoker’s corpse. Calyptra moths could give less than two shits about your cute little set of flower boxes outside, and are more interested in bringing pain to your veins.

That “butterfly” that supposedly flaps its wings and sets off a chain of meteorological reactions that culminate in a hurricane generating across the world? Yeah, that evil little bastard responsible for all that chaotic destruction (and by association, that godawful mid-2000s sci-fi thriller with Ashton Kutcher) was most certainly a moth named Calyptra.

Fig. 1, aforementioned evil little bastard

Only the males of the vampire moth indulge in the “scarlet nectar,” employing their surprisingly tough, rigid tip of their proboscis to puncture flesh, and unleashing a series of spring-loaded hooks that keep them from dislodging easily…allowing them to drink at their leisure. Calyptra moths tend to target large mammalian herbivores, like buffalo, elephants, and rhinoceroses as reservoirs of blood to stick their Straws of Torment into, but on a few occasions, humans have been…fortunate…to know the moth’s bite (particularly when it’s C. thalictri).

Let me be clear on the differences between being bitten by a vampire moth and being bitten by a mosquito. Female mosquitoes have highly specialized mouthparts molded by evolution into a sleek hypodermic needle, delivering a swift dose of blood-thinning venom after an expertly placed pinprick, followed by a seamless transition into hardly noticeable blood slurping. In contrast, vampire moths are working with a tool that is far better suited for piercing the skin of fruits in the search for sugary juices, than it is for living animal flesh…and this is because, unlike mosquitoes, and despite their name, vampire moths are not purists when it comes to the sanguinary dining thing. Male vampire moths are “facultative” blood feeders, meaning that, to them, blood is a “sometimes food”, and their diet is also rich in the happy, normal, not-you-or-me regions of the food pyramid. Calyptra and closely related moths are known for their ability to use their burly proboscises to tear into fruit for sustenance…obviously in rabid, vindictive frustration from getting to the flower weeks too late for nectar. This tool, wonderfully useful in giving a plum the worst day of its life, is woefully unsophisticated (compared to the mosquito’s instrument) when applied to big, ambulatory critters with touchy, inconvenient things like nervous systems.

The difference between getting bit by a mosquito and getting bit by a vampire moth is like the difference between having your blood drawn by a phlebotomist with a quarter-century of training and experience, or by Kevin, the disheveled tweaker with the “can-do” attitude secretly squatting in your neighbor’s shed. The mosquito gets the job done relatively painlessly and quickly with incomparable surgical precision. The vampire moth, on the other hand, opts for enthusiastically digging around in your forearm with a rusty lawn dart.

So, vampire moth bites are crude and painful for their entire duration because, unlike mosquitoes, these creatures don’t make their living from blood. There’s not as much reason to keep you or any other source of blood unaware of their feeding, and their craft is not honed or specialized. This is also part of the reason why these moths don’t pose any threat to people by way of disease transmission; the frequency of biting is too low and the feeding system is too inefficient. The frequency of hematophagy varies fairly widely among vampire moths, as well as the capacity to dig into fruits, with species capable of exploiting fruits along certain sections of a gradient of fruit skin thickness and hardness.

Inferences based on genetic studies of evolutionary relatedness among the group, seems to indicate that the evolution of the behavior doesn’t follow a pattern of supplantation of more primitive, vegetarian feeding modes (nectar, soft-skinned fruits) with more derived ones (hard fruits, blood), but rather that more recently evolved vampire moths simply have more of the feeding strategies available to them. More primitive moths in the group might only be able to probe squishy fruits, but moths like C. thalictri can have it all; thin-skinned fruits, thick-skinned fruits, fruits with a tough rind, people…you name it.

But why all the drama and gore either way? Why has Calyptra developed this propensity to temporarily ditch soft drinks, go full-on fucking Dracula, and cut straight to the hard shit? Flowers and fruit seem good enough for the rest of the moth and butterfly clan, so why does the vampire moth have such a needy palate? Well, the reason may result from the practice of “mud-puddling”, which is an activity that involves far more bugs and far less mud-wrestling sexy times than you’d think (don’t lie, I know you were imagining it). If you’ve ever seen a bunch of butterflies very obviously touch down next to a shallow pool or puddle and gather around the muddy water’s edge like wildebeest at a watering hole, then you’ve seen mud-puddling. It’s very common among butterflies and moths, and the goal of mud-puddling is to suck up nutrients and salts found in things like mud, dung, and occasionally decaying matter (plant or animal). Mud-puddling tends to be a male-only hobby, and it’s thought that acquiring all these extra goodies has a key role in reproductive success. Males are often observed “gifting” females with these nutrients and salts alongside their sperm contribution. It’s essentially a ridiculously late, coitus-adjacent means of presenting a girl with flowers.The extra nutritive boost can be of great value to any upcoming larvae to originate from such a pairing, since many caterpillar species feed on plants that are sparse in nutrients. It is likely that blood-feeding, rather than serving as a food source for the adult male moths, provides another advantageous avenue for aspiring, prospective dad Calyptra to provide his progeny with health and vitality, as blood is literally piped around animal bodies as a nutrient, mineral, sugar, and amino acid smoothie.

Oh, and if you are currently residing in latitudes to the north of the temperate and tropical latitudes of Afro-Eurasia, and smugly reading this and acknowledging your comfortable space far outside the reach of the vampire moth…listen up.
Calyptra has been found, in recent years, to be expanding its range poleward into northern Europe, turning up in places like Finland, which is a place normally considered too cold for these bitey assholes. It’s very likely this invasion is due to recent, rapid, human-driven climate change effects, and that their residency in the north will become not only more extensive, but permanent. I’m relatively certain “influx of fucking blood-sucking moths” is some sort of karmic punishment for what humankind is currently doing to the polar bear.

“Alright,” you concede, “moths can be a little intimidating and off-putting. But not caterpillars! Those younger, squishier, tube-shaped versions of moths are just doofy, derpy, compulsively overeating herbivores! The adorable little buggers couldn’t be a threat to anything if they tried!”

Oh come on! It’s giving me puppy dog eyes!

To illustrate just how wrong that is, allow me to take your mind’s eye out into the middle of the Pacific Ocean, to the tropical archipelago where I make my home; Hawai’i. Hawai’i is celebrated the world over for its jaw-dropping natural beauty, with imposing, steep, eroded mountains covered in lush vegetation dropping dramatically down to idyllic white sand beaches. It’s touted as “paradise”, and after living here for a year and experiencing not a single day below 60 degrees Fahrenheit, and the freedom to snorkel along coral reefs and hike in gorgeous tropical rainforest year-round, I can definitely agree with the common, mythic conceptualization of the island chain. In addition to being so eye-wateringly beautiful, Hawai’i is a remarkable laboratory of evolution, given its location thousands of miles from the nearest landmasses. A large proportion of the land organisms found in the islands are “endemic”, meaning that they are found nowhere else in the world, having evolved in complete geographic isolation from relatives on the mainlands of Asia and the Americas. They range from brilliantly-colored forest birds like the ‘i’iwi, to hardy plants found only along the slopes of volcanoes like the silverswords and greenswords, to a unique subspecies of bat. In keeping with the paradise aesthetic, most of what has evolved out here in the middle of the ocean isn’t much of a threat to jack shit, and especially not to invasive species brought in by human colonizers, which have, depressingly, turned Hawai’i into a laboratory of extinction in addition to one of evolution. With a dearth of many natural predators, whatever lineages were able to make it out here and spread across the islands often let down their defenses after millions of years of vacation. Just ask the moa-nalo, a group of geese-like birds that discarded their ability of flight. They suddenly, and curiously, dropped off the face of the Earth immediately after Polynesian settlers first arrived in the archipelago…it’s almost as if they were easy pickings for food. Weird how that works.
So yeah, a lot of the wildlife in Hawai’i are steeped in their own sickeningly sweet levels of isolation-driven innocence and vulernability. I mean, hell, even the spiders here have permanent happy faces plastered on their chipper selves.

This is not a place where you’d expect to find carnivorous goddamned caterpillars, but that is exactly what Hawai’i has to offer.

The caterpillars belong to moths of the genus Eupithecia, which are a highly speciose, diverse group of small, drab, nondescript moths also known collectively as “pugs.” They are found all over the world, and the vast majority of the time, their caterpillars are conventional, adorable, inchworm-like things, doodling around and munching on flowers and leaves and generally being about as terrifying as a clump of pocket lint. But there a number of species in Hawai’i that have evolved into skilled ambush predators, lashing out at unsuspecting insects like a demonic spaghetti noodle and clasping them in spiny claws, turning their elongated bodies into a ravenous grappling hook, with all the merciless, direct brutality of a Mortal Kombat finishing move.

“Get over here!”

Good lord, is nothing sacred in this world? The last time I checked, the Very Hungry Caterpillar ate a lot of shit, but the still-beating heart of a fresh kill wasn’t on the menu.

Hawaiian Eupithecia caterpillars are a product of that evolutionary laboratory I was talking about. The other side of island critters no longer needing anti-predator defenses is the precarious ecological hole left by, you guessed it, no predators. The job position for predatory insects was left wide open since things like mantises weren’t able to survive the extreme distances out to the islands…and these caterpillars have eagerly filled it.

These little grubs of destruction have evolved a simple and effective means of striking fear into everything that flits and buzzes through the rainforests of the archipelago. They, not unlike many of their closest mainland relatives, mimic a small twig, making their gray and brown mottled bodies rigid and still, tightly gripping a branch with their hind feet and keeping the nasty business end erect and ready for action (note to self: Erect and Ready for Action is a great title for a porno). In this position they wait…and wait they do, until some terminally unlucky fly or beetle strays just a little too close. As far as other insects are concerned, the butt end of the caterpillar is just a knobby extension of a branch…and totally not studded with sensitive bristles that instantly alert the head end that dinner has arrived, prompting a lightning fast spasm that brings Mr. Fruit Fly face to face with three pairs of sword-shaped limbs and a glistening battery of sharp, salivating mandibles. Eupithecia arches itself in a tight loop, and like a bullwhip tipped with meat hooks, dispatches its target with deadly speed and accuracy…like a wormy falcon snatching a sparrow out of the air with its talons. The hapless insect doesn’t even have a chance to react, its life is pathetically brought to an abrupt end by the world’s most murderous larva.

Aw, it’s kind of cute; like a sleepy tiger licking its paws after disemboweling your whole family.

It’s possible that there are a number of traits already a part of pug moth caterpillar biology that may have served as “pre-adaptations” to a predatory lifestyle, and made transitioning from passive vegetarianism into being the most malicious maggots in town particularly easy. Their characteristic paroxysmal attack method might have its evolutionary origins in a defensive snapping behavior, in which an attacking bird or lizard might be stunned by the quick movements just long enough for the caterpillar to flop down to safety. This behavior could have been co-opted into their hunting technique quite effectively.The evolutionary transition to an insect-based diet might have been eased by Eupithecia’s tendency to consume specific parts of plants, like flowers along with their protein-rich pollen. A diet already pre-adapted to consisting of high-protein foods may have made switching from salad to steak easier than it would for many other vegan creepy-crawlies.

“Ok,” you start, “Hawai’i’s got some pretty homicidal moth babies. It’s a good thing I’m not a bug, or then I’d have something to worry about. Luckily, there’s no caterpillar that could possibly impact my health or well-being.”

Yeah, no. Not even fucking close.

Meet Lonomia, a genus of moths found in South America that are closely related to the stunningly patterned and gigantic atlas and luna moths. However, the adult Lonomia moths are far more conservative in coloration than their more famous family members, choosing to go with subtle camouflage against the backdrop of their woodland home. This is not an unusual strategy among moths.

Oh, you look like a brown leaf? Wow, groundbreaking creativity.

Lonomia caterpillars are also gifted with the ability to blend in, but are covered in short, pale, spiky clusters of hairy projections, thus disguising themselves instead as diminutive Guy Fieris, sent to Brazil to film a special episode of “Diners, Drive-Ins, and Dives.”

“Welcome back to Triple-D! I’m on my way down to Flavortown to score some grub! Haha, get it?!”

“So, that’s it? That’s the big bad caterpillar? Why, I can crush that fuzzy mulch-muncher into a moist smear on the bottom of my boot with no problems whatsoever.”

Yes, but you’d better make sure it’s a boot, and you’d better make sure you throw that boot away when you’re done, making damn sure you don’t touch the bottom of it without thick-ass gloves on.

Lonomia caterpillars’ hazard doesn’t lie in a predatory inclination, or an unpleasant bite like that of the vampire moth. Lonomia is dangerous because of the thick forest of branched spines (called “scoli”) which harbor hollow bristles, each one loaded with its own lovely little dose of venom. These types of defensive hairy structures are common in many types of caterpillar, and many people can get unpleasant and painful skin reactions from touching them and becoming envenomated. But Lonomia‘s special blend of toxins is so devastatingly potent that interactions with this caterpillar, like simply brushing up against it, has lead to human deaths. Yes, this is a caterpillar that can kill you fucking dead.

All species in this genus are highly venomous, but one species in particular, Lonomia obliqua, holds the “honor” of bringing forth the highest frequencies of severe reactions to the venom. Not everyone who accidentally collides with these cryptic caterpillars when moving through the forest (as is typically the way in which the envenomation occurs; when hands and forearms are clearing away brush and inadvertently smack into a feeding Lonomia), but the mechanism by which these perilous pincushions deliver their venom and how this venom does its dark deed remain the same:

The venom is produced within hair-like structures, called “setae”, situated on the scoli. Unlike many other venomous animals, which have a single, definable “venom gland” that secretes and stores the venom, Lonomia, instead, has an array of microscopic vesicles (little sacs) embedded within the cells making up the inside layers of a hollow, tubular tract inside of these bristles. The diabolical cocktail of toxins is slowly secreted from these cells, and pool in this cavity at the base of the tip of the seta. And there it sits. Waiting.

The tip of the bristle, hard and chitinous, is fashioned in such a way that there is a “weak spot”, a pinched line of fragility, near where this internal venom reservoir sits, such that upon just the slightest irritation (like a hand coming along and embedding the toxic needles within the skin), it breaks off like a glass ampule.

From Veiga et al, 2001, showing the end of a seta, equipped with detachable tip and venom chamber.

The tip busts open like a champagne bottle, releasing a lovely, effervescent torrent of horrific toxins right into the bloodstream of whatever poor soul owns that ill-fated hand.

Initially, the stinging sensation from the wound is hardly noticeable, and certainly not something you’d feel the need to stop and inspect what happened, especially if this happened right in the middle of vigorous, sweaty outdoor work. So when the true effects of a particularly bad envenomation start to take place in the coming hours and days following contact with the caterpillar, it may come as an unwelcome surprise to the victim, who may not actually remember getting bit or stung by anything at all.

And what exactly are these effects? Lonomia has a venom with amazingly strong anti-coagulant and anti-fibrolytic properties…meaning that it stops your blood from doing that fairly important function of clotting. If you are unfortunate enough to get a high enough dosage of venom, your blood not only ceases to clot, but your entire circulatory starts…well…leaking. As you might have guessed, when all your internal plumbing suddenly begins to drip like a loose sink pipe, that can be a huge goddamn problem. Envenomated folks can often present with a “hemorrhagic syndrome” called lonomiasis, which most commonly results in widespread bruising in places where your blood is pooling out of your toxin-ravaged circulatory system, making you look like you got worked over real good by an army of angry people with crowbars and bats. All of this happens in nearly complete silence, generally undetectable to the victim in the period of time following the sting. If you are pricked, a great deal of time can pass in complete ignorance of the growing, gushing, collective fount of internal bleeding caused by the venom, causing your organs to marinate in this flood of what should be oxygen-rich juices, disastrously re-routed away from their crucial role in keeping you alive.
In the most extreme cases, this can snowball into brain hemorrhages or renal failure, which of course can precipitate death from catastrophic brain and kidney damage.

Death by caterpillar is not the preferred way to exit this life.

Luckily, about only 2% of those suffering from such Lonomia-related accidents actually perish. Also, on the bright side, the stupendously potent anti-coagulant properties of the toxins found in Lonomia venom have potential medical applications, specifically in the treatment of maladies in which too much clotting is a problem. So, despite the undoubtedly real dangers posed by this moth’s childhood phase, Lonomia might eventually end up indirectly saving far more lives than it has ended.

Moths are fantastic animals, and live far more interesting and dynamic lives than we tend to acknowledge. Whether it’s the unsettling sex-balloons of Chionarctia, the barbaric bite of the vampire moth, the rapacious tyranny of Hawai’i’s most vicious caterpillar, or an insect armed with one of the deadliest touches on Earth, it’s abundantly clear that some moths also certainly possess a unexpected capacity for horror, and command a nervous respect from humankind that they rarely receive.

Image credits: Introductory moth image, Chionarctia nivea, vampire moth, “cute” caterpillar image, Lonomia adult, Lonomia caterpillar, carnivorous caterpillar gifs originally from footage from this BBC Two clip

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Eucalyptus regnans, Tallest Tree in the South

I like really tall trees.

I suppose the possession of this adoration of our planet’s living, heaven-raking spires comes as a kind of birthright. I grew up in the Pacific Northwest, an area not only richly coated with swaths of the densest temperate rainforests in the world, but also the tallest forests in the world. I came of age spending a great deal of time hiking and navigating forests largely consisting of several tree species that are among the world’s tallest. Coast redwood (Sequoia sempervirens), douglas-fir (Pseudotsuga menziesii), and Sitka spruce (Picea sitchensis) are all found in the lush coastal forests of Oregon and far Northern California where I spent many long, summer days of my youth; each of them generally regarded as being within the top five tallest tree species on the planet, based on the consistency and frequency of superlatively monstrous individuals within each. Even the “smaller” trees in the region seem to reach uniformly towering heights. Western redcedar (Thuja plicata) can top out at 200 feet (61 m) or more above the soft, spongy soil of the dark, coastal woods of Washington and Oregon. Western hemlock (Tsuga heterophylla), a very common sight in the Pacific Coast Ranges, can easily grow to some 250 feet (76 m) at its droopy crown. The bottom levels of the canopy in a Pacific Northwestern old-growth rainforest can potentially be no less than 150 feet (46 m) high, which is a value not often matched in any other forested region on Earth.

A shaggier version of myself standing with the Quinault Lake Redcedar, the largest western redcedar in the world, on Washington’s Olympic Peninsula in June 2011 (Photo credit: Werner G. Buehler)

It’s no wonder that growing up immersed in this place has left me with a love for these great trees; old-growth forests full of venerable, enormous trees are incomparably majestic places. The sense of perspective and scale that these trees provide is invariably humbling. It’s difficult not to walk alongside them in a kind of hushed reverence, as if you were traversing the floor of an ancient and solemn temple or cathedral, one crafted from humongous, gnarled pillars of wood and moss, rounded with smoothed with deep time and dark silence. The temperate rainforest springs to life in intense bursts of emerald from wherever these trees have embedded their water-ravenous feet, with lithe lances of ferns and the ghostly baubles of root-associating mushrooms erupting wherever soil space is available. These dampest and darkest of woods, blanketed from the sun a football field’s length upwards, have been described as primordial, as a place of senescence and decay, but I think this is a misplaced conceptualization. The sites where the greatest of these trees grow is positively choked with life; life that clings to and parasitizes other life, life that reaches achingly skywards in even the weakest, most diluted sunbeam to touch down on the forest floor. In my mind, these are places of as much birth and flourishing as they are museums.

This aesthetically spell-binding quality, mixed with these forests’ complex ecology and somewhat unique, insular propensity to harbor endemic species…creatures found nowhere else in the world…is what persistently attracts me back to them time and time again (and also inspires me to write about themmultiple times…because I’m a little insufferable).

It is these types of places, misty, verdant groves of titanic conifers, that come to the mind of most when they envision the world’s tallest trees…granted they call the Northern Hemisphere home. It’s somewhat widely known that California’s coast redwoods are the world’s tallest species, and across the North American continent the sheer size of Pacific Northwest forest trees is no secret…especially when compared against the far more “compact” deciduous trees that are common on the Eastern Seaboard. But a very close contender for the title of the most gravity-taunting plant in the world comes from a location not often associated with impenetrable forests. One of the tallest organisms on Earth is an altogether different kind of plant than the behemoth redwoods, and it hails from the opposite side of the globe from the dewy haunts of Cascadia…a place far more associated with rust-colored, alien deserts, blinding heat, and a faunal assemblage that constitutes the world’s largest bucket of shorts-soiling “hell fucking no.”

I’m of course talking about Australia.

Yes, Australia is a place of extremes…where the venom flows like water, the coral reefs are supersized, and summer turns the landmass into a not-so-metaphoric broiling pan of unending solar-powered punishment  (one that keeps getting hotter). From a biological perspective, Australia is a continent perpetually locked in rebellious teenager mode, deviating from the rest of the world’s biota and letting its freak flag fly proudly for millions of years in a parade of pouches, flightless birds, weird plants, fangs, spikes, and scales. It is therefore quite fitting that one of the tallest trees in the world, the only one in the top five that is not a conifer, in pure contrarian style, is Australia’s Eucalyptus regnans…the “mountain ash” or “swamp gum.”

Eucalyptus regnans holds the title of the world’s tallest flowering plant, or “angiosperm” (which is in contrast with the coniferous redwoods, firs, and spruces…which are cone-bearing “gymnosperms”). It is also the tallest tree in the Southern Hemisphere, and the only trees to compete halfway decently for this distinction are other members of the genus Eucalyptus. The only explanation I can think of is nepotism…..

…or, alternatively, that Eucalyptus is a highly diverse group of over 700 species of plants that dominate the Australian flora, with an extensive array of growth forms and habits, and that a giant species or three thrown in is not by itself unusual. Eucalyptus is known for its role as koala chow and its Altoid-scented foliage, as well as a particularly attractive, psychedelic species native to Indonesia and the Phillipines, “rainbow eucalyptus” (Eucalyptus deglupta)…which looks like it was bred by Willy Wonka’s horticulturist.

Seriously, this thing looks like it tastes like a Laffy Taffy.

More broadly, Eucalyptus is a part of a large, wide-ranging family of flowering plants found in the warmer latitudes; Myrtaceae. The family contains a staggering number of species of plants (more than 5600 estimated), including well-known examples like allspice, guava, clove, myrtle, and the enigmatic, endemic (and threatened) ohi’a of the Hawaiian Islands. They are all united in having hard, woody stems and generally having obvious, brushy flowers that strongly resemble exploding fireworks.

This is a variable and successful group of plants, and the stately mountain ash is a jewel in this family’s crown.

It grows in the relatively cool, mountainous, far southern Australian states of Victoria and the island of Tasmania in upper elevations. Mountain ash inhabits the rainy “wet eucalypt” forests that characterize much of the very southern tip of the Great Dividing Range, where it grows at a breakneck rate of roughly one human height every couple of years. The tree grows faster than the mammoth conifers of the Northern Hemisphere, but ends up, in maturity, being a less voluminous, lanky sight to behold; a thin, columnar colossus culminating in a noble tuft of aromatic, evergreen leaves. The mountain ash is to the coast redwood/giant sequoia as Manute Bol is to Andre the Giant. As a pepperoni stick is to a pork chop. As a taquito is to a burrito.
Anyways, you get the point, and I’m going to stop before I make myself hungry.

Some exceptionally altitudinous mountain ash specimens can exceed 300 feet (91 m) in height after as much as four centuries of growth. As of 2014, the largest living mountain ash is the aptly-named (on account of its 100 m (327 foot) height), baronial Centurion, a tree from Tasmania. This sits solidly in the mid-range among the tallest Californian redwoods, but there is an account of a mountain ash from Victoria in the late-1800s near the community of Thorpdale that was measured at about 375 feet (114 m) in height…which would not only put it within mere feet of the tallest reliably recorded tree ever (a coast redwood named Hyperion, at just over 379 feet), but would mean that at the time, it would have been the tallest tree known. The Thorpdale tree was felled more than a century ago, but the site of its former stump remains marked to this day.

“What are these? Cars for ANTS?!” No. Full-sized cars. King-sized forest.

Most eucalypt species have a close relationship with the fires that regularly blaze their way across the dry woodlands and plains that border the vast interior desert of the Australian continent. They have a suite of adaptations that allowed a lineage of plants that, tens of millions of years ago, originated in the region’s rainforests, to survive the aridification of Australia and to prosper over a newer, drier continent: stringy, flammable bark, oil-rich leaves that break down very slowly in the leaf litter, and, commonly, a means of rapidly re-sprouting from fire-protected seeds and/or resilient buds hidden underneath the bark, stimulated to grow after severe damage to outside layers in a bushfire. The majority of eucalypts in these dry, open woodlands are reborn again and again from frequent fires. On hot, dry season days when the sky is roiling with angry, charcoal-colored storm clouds, it is the crack of thunder and lightning that marks their labor pains.

However, the relatively moisture-loving, rainforest-associated mountain ash is a bit of a wuss, comparatively, when it comes to fire. While the species certainly has the dilapidated, vestigial remains of the structures associated with post-fire sprouting from the charred bark, the main strategy appears to reproduce from the seeds left behind following an especially damaging fire (and spectacularly so, with as much as 2.5 million seedlings per hectare (an area about the size of a baseball field) sprouting from seed following a burn…obviously, this is pared back substantially as the trees mature and compete with one another for light and resources in a case of the most cutthroat sibling rivalry conceivable). If the fire is intense enough, the mountain ash often dies outright, never to rise again from the ashes like a Phoenix, save for its genetic torch being carried forward by great multitudes of its progeny.

Mountain ash is superbly adapted to deal with the effects of relatively infrequent fires. It can take a good decade or more after a fiery armageddon for the new crop of young trees to be mature enough to produce seed, so if another super-fire cuts through the area before that point, the entire region becomes effectively deforested of mountain ash. This is obviously a big damn problem, but under normal circumstances, the chances of catastrophic engulfment with earth-cleansing, surface-of-the-sun scale hellfire occurring more than once per decade in the same spot is fairly low.
But…the key word is “normal” in “normal circumstances.”

I linked to a source several paragraphs above that illustrates that Australia is getting hotter as global, human-induced climate change progresses. The other side of that doom-and-gloom coin of the heat being imminently and permanently cranked up to 11 is the fairly solid recent prediction (from CSIRO, Australia’s national science agency) that in the coming decades, rainfall will decline in the range of mountain ash in southern Australia, and severity of drought conditions will increase. Both of these factors contribute heavily to promoting not only more frequent fires, but the types of destructive events that bake the soil into blackened sterility. There are predictions that suggest that the wet, southern, mountain forests of Victoria and Tasmania might not have quite the same jump in overall risk of severe bushfires in response to coming climate change that other regions of the continent will likely endure, but mountain ash habitat will also surely suffer substantial drops in rainfall and an uptick in the amount of that moisture that is evaporated away, sucked right into the unyielding blow drier that is Australia’s future atmosphere.

The seemingly inevitable transition of every single corner of Australia into a fucking tinderbox isn’t a particularly potent threat to mountain ashes all by itself. There’s a second element that comes into play with the relentless dehydration of the continent; one with a very direct human component. Can you guess what it is?

I’ll give you a hint: it rhymes with “blogging.”

Mountain ash is a valuable source of lumber in this part of the world, and, curiously enough, it turns out that threshing the everloving hell out of old-growth stands, and laying immense tracts of forest bare for the timber industry, has lasting, awful ecological effects. The double-whammy threat to these trees comes in the form of the junction between fire susceptibility and timber harvest practices. Mountain ash forests that are 1) younger and 2) fairly homogenously so are pitifully prone to the super-hot, super-aggressive fires Australia has become known for. Until mountain ash grows up to be big, strong, and resilient against the licking of flames, the young trees are as vulnerable to incineration as a box of kerosene-soaked matches at a KISS concert. If these baby-faced whippersnappers are all about the same size/age as well, then there isn’t much diversity, tree to tree, in the forest’s resilience against fire; the fire can spread completely unimpeded due to the absence of burn-slowing bigger individuals.

The most dramatic force shaping mountain ash forests towards a uniform crop of spark-wary sitting ducks is that of unfettered clearcut logging of these trees. What occurs is a tragically tight positive feedback loop that begins to “trap” entire landscapes in a self-perpetuating process of rapid change and potentially irreversible shifting to an entirely different ecosystem structure at the elimination of what once was. Logging promotes the growth of fire-prone mountain ash forests, and the subsequent increased fire activity and severity constricts the ability of that area to allow the re-establishment of old-growth forest…which encourages yet more bushfires in young, dense, regenerating groves of trees.

At this point in time, mountain ash isn’t immediately faced with the dodo’s fate; there’s no indication that the tallest flowering plant in existence will die out in the next couple of decades. As far as we can tell, Eucalyptus regnans is rather “safe” at this moment. However, mountain ash still isn’t specifically protected in Australia, and timber harvest continues largely unabated. The potential threats to mountain ash haven’t yet been evaluated by the IUCN (International Union for Conservation of Nature) as grave enough to warrant the recommendation of protection from exploitation, but there are a couple reasons why we should be concerned with still declining numbers and the health of mature mountain ash forests.

The first of these is that, like other huge, forest-dominating trees like redwoods and sequoias, the mountain ash has a wide-reaching role to play in its ecosystem, and a great many species depend on its presence for their own survival. When you are big enough to influence the entire dynamic progression of the little world that surrounds you, any change or absence has a reverberating, “echo” effect. The best example of this in mountain ash forests is the stubborn dependence of the Leadbeater’s possum (Gymnobelideus leadbeateri) on the accessibility of a very specific mix of moderately mature eucalyptus trees and wattle (Acacia). This nondescript, nocturnal, squirrel-like marsupial, closely related to the watery-eyed, frenetic, more publicly familiar sugar gliders, is now found only in a tiny stretch of forested uplands in central Victoria. It is a victim of the punctuated, but extensive, loss of mountain ashes old enough to have tree-holes as a daytime refuge (because apparently nocturnal animals aren’t big into the whole good ol’ vitamin sunshine thing); cataclysmic fires in the region, paired with regular clearcutting, have decimated available habitat for the possum in recent years, causing a drop to an estimated 1000 remaining animals in the wild. That may seem like a lot of Leadbeater’s possums left in the world, but in reality, a series of marginally inferno-y summers could evict these little guys off the planet for good. Considering that every single individual alive is now constricted to an area smaller than that of metropolitan L.A., the idea of them getting snuffed out by a bad case of climactic heartburn, or indirectly through a temporary spike in the price of mountain ash timber, doesn’t seem all that ridiculous. If you aren’t yet feeling a bit morose about the possum’s likely eventual, brutal blaze-and-blade initiated gentrification into oblivion, please consider that Gymnobelideus leadbeateri continuously makes a face like you just stole food out of its mouth and told it its birthday was canceled:

Critically endangered? More like critically adorable.

Here, the equation is simple. No mountain ash = no Leadbeater’s possum. No Leadbeater’s possum = no inspiration for a new Pokemon in the next series of games. No new Pokemon = I actually have to grow up and begin behaving like a fully functioning adult human.

This is an unspeakable tragedy.

The other reason the loss of mountain ash forests is worrisome, in particular the old-growth forests full of the largest trees, is that gargantuan trees are uniquely suited for siphoning off the carbon dioxide pollution responsible for global climate change, and converting it back into biomass. Forests, more broadly, are the truthfully important engines on land for grabbing carbon out of the atmosphere and incorporating it into new growth…but for the world’s largest trees (like mountain ash and redwoods), with an increase in size and age, that capacity for transforming greenhouse gases into board feet of lumber climbs in scale almost exponentially. Rather than slowing down and taking it easy on the growth as they enter retirement age, the world’s giant tree species appear to do the opposite, ratcheting up their efficiency as a “carbon sink” and accelerating their carbon mass gain. Big trees, not unlike humans, tend to pack on the pounds faster in their golden years.

Since one big, ancient mountain ash or redwood far more adequately gobbles up greenhouse pollutants year to year than a stand of dozens of smaller, more junior trees, we should start considering the last remaining fragments of old-growth forest, specifically, as a minor means of mitigating some of the output of global carbon dioxide emissions; these exemplary trees are worth saving as both crucial, ecosystem-influencing habitat for scores of other species, as well as a drain on the atmosphere-bound outflow of greenhouse gases. It’s important to note that mountain ash specifically has been shown to have groves that are estimated to be the most carbon-dense in the world, hinting at their potential as especially effective carbon traps. If we lose the biggest mountain ashes, we simultaneously shoot ourselves in the foot a little bit on combating climate change.

Since we now recognize the utility of incredibly large trees as veritable carbon vacuums, we would be wise to understand the scope of what kind of a loss it would be to have these plants fade into extinction. Mountain ash, as a species, seems to be holding on (for now), but the coast redwood was, depressingly, newly included in 2013’s IUCN Red List as an endangered species, still in decline from human harvesting and encroachment.

We are just now starting to understand the most tenuous, subtle relationships between the most massive organisms (among which the mountain ash is a prime example) to ever evolve on Earth, and their surrounding neighbors…both in a direct, ecological framework, and indirectly through recycling climate-altering carbon dioxide. Hastening our pace on keeping the Tallest Trees in the South, or the North, or wherever, from collectively biting the dust at our own misguided and careless hand does far more than save some of the handsome hiking and photography locales we supposedly love so much…it also avoids a world of ecological pain.

Because that’s the thing about really big trees, evidently; the taller they are, the harder they fall.

Image credits: introduction image of E. regnans, rainbow eucalyptusmountain ash with cars, logging photoLeadbeater’s possum

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.

Boxfish: Little Fish, Big Toxins

The boxfish.

Most of the time, I use this blog to blather on and on ceaselessly about all the things about life on this planet I find inescapably fascinating. While all of my exposition on killer fungi, badass birds, weird plants, or whatever obscure, bizarre, horrific, extinct monstrosity wandered into my search history that week is charming (obviously) and fun and all, I don’t often indulge in not only talking about the things that I think need to be shared, but things that are also very directly related to my scientific, academic interests. But, today I shall pander to myself and the relatively narrow realm that constitutes my research interests in the hope that you, dear reader, can push through the voluminous, insatiable outwards expansion of my own ego and acknowledge that my currently proposed study organism for my PhD research, the proud, doughty boxfish…is pretty goshdarned fucking cool.

While I plan on investigating certain nuances about the genetics and evolution of this special group of fishes, the topic of this post isn’t on the subtleties of things like gene flow between populations and speciation, but instead on an incredible, noxious, chemical adaptation that is unique to the boxfish.

But first…what exactly is a boxfish? Boxfish are small fish (between about 5 and 18 inches long, but most are at the low end of that range) that frequent the shallow areas of the warmer parts of the world’s oceans, like coral reefs and seagrass beds. They spend their lives passively pruning algae and small invertebrates like crustaceans, worms, and sponges off rocks and coral with their tiny, delicate mouths. They, as a group, are united in having a body made conspicuously rigid with hexagonal, bony plates fused together to form a hard, yet light-weight shell that encircles their interior, “real” skeletal framework. This shell (which has recently been used as bionic inspiration for automobile design) often has modestly rounded corners, and makes the animal distinctly rectangular in overall shape…hence the “boxfish” name (many species are also referred to as “trunkfish,” and there a some species with preposterously unintimidating horns called “cowfish“). This is an animal that is too hip not to be square.

So, this full-body shell results in the boxfish having a skeleton that essentially looks like a decapitated skull. Similarly to a skull, there are precious few holes in the cage of bone, and the formidable armor only opens up for the eyes, puckered mouth, fins, and tail to peek out into the water. When desiccated corpses of boxfish wash up on beaches, their remains resemble the forgotten, bleached craniums of ill-fated livestock out of a stereotypical, “harsh” cartoon desert.

Photo taken shortly before a tumbleweed rolled into the frame.

Being a living tank confers some benefits. The most obvious of these is that it makes you really damn difficult to eat. Not too many predators jump at the opportunity to slam their pearly whites down on what is effectively the peach pit of the sea. Even for big, powerful, voracious, predatory fish, nomming on boxfishes is less like satisfyingly splintering a hard taco and more like trying to chew a kneecap; it’s a poor decision for all parties involved. Because of this heavy armor, boxfish aren’t exactly the fleetest fish under the waves. Boxfish are only able to propel themselves by using rapid undulations of their itty-bitty fins and exposed tip of their tail, as their entire body has been made inflexible by their bony shell. This is in contrast to most fish, which use strong muscles running the length of their bodies to move their tails side to side, torpedoing their streamlined forms forcefully through the water…and rapidly out of the toothy grasp of whatever is trying to eat them. Boxfish have made an evolutionary tradeoff, sacrificing speed and agility for enhanced defensive capabilities. Also, what they lack in power and evasive skill, they make up for with precision, being able to turn on a dime and dart into secluded overhangs and holes in the reef when pursued as a meal. As someone who has personally sought capture of these little creatures on many occasions, I can attest to their impressive maneuverability, leading to much frustration on my end. Frankly, it’s remarkable how quickly one can go from “aw, look at this cute little guy” to “oh, don’t you run away from me, you miserable son of a bitch” when you need to bag these buggers.

The strategy of hedging your reproductive future on simply being exceedingly unappetizing at the expense of athleticism is not an evolutionary route commonly taken by fish…but boxfish and all their close relatives have turned this approach into an art form. By “close relatives” I mean the order of fish to which boxfish belong, Tetraodontiformes. Tetraodontiform fish, almost without fail, have followed this unconventional path of taking the slow lane while arming themselves with a whole host of tools crafted by evolution to convince everything else in the ocean that, just like a questionably odoriferous bowl of tepid potato salad, they are a meal that just isn’t worth the pain. This coalition of fish, of which boxfish represent a single family (Ostraciidae), are “highly-derived”, meaning, in this case, that they exhibit a high degree of evolutionary modifications that are unique to that group; simply put, tetraodontiform fish are exceptionally, fundamentally different among their finned, gilled brethren. The group, over the course of its tens of millions of years of evolutionary history, has set along a curious trend of relentless reduction of all their fishy features. They’ve lost dorsal fins, many entire bones and portions of their skeleton (just little things…you know, like ribs), simplified their gill coverings, and shrunk their mouths (but kept their jaws big and powerful). They’ve condensed a mouthful of chompers into a handful of hard, strong teeth forming a beak-like shearing apparatus. They’ve even downsized the scope of their genomes (the entirety of the genetic material of an organism), multiple, independent times across several families, and one species, a freshwater pufferfish from Japan, has the smallest vertebrate genome currently known.

This overarching trend of maximum efficiency has been accompanied by not only the development of a wide array of body shapes, perhaps more diverse than any other order of fish, but also an impressively varied range of anti-getting-incorporated-into-the-food-chain measures. Examples abound, and tend to be grouped by family. Boxfish have teeth-unfriendly armor. Porcupinefish can bloat up to two times their original width, often lodging their spiny, spherical selves in the soft craw of whatever tried to choke them down. Triggerfish and their close relatives, filefish, can erect and lock into place sharp dorsal spines that make them very hard to remove from tight spaces within the nooks and crannies of the coral reef. One small family, the molas or ocean sunfishes, are covered in rough, sandpaper-like skin, and grow to such outlandish sizes that few things could tangle with them even if they tried. Pufferfish obviously have the ability to turn themselves into unchewable living balloons, but many species have tissues laced with a toxin so monstrously potent that even the most minuscule amount of exposure is more than enough to leave a human morgue-bound.

Boxfish hail from a line of fishes that are leisurely-swimming, anti-predator toolboxes. Tetraodontiformes, as an order, is a veritable Swiss Army knife of inventive evolutionary gadgetry; a fun-bag of bony plates, spines, levers, inflatable bodies, thick skin, and deadly chemical cocktails.

Adding to the extensive list above is one final trick up the tetraodontiform’s wet, salty sleeve…and it belongs to the fish with angles that’s hard to mangle…the boxfish. Like puffers and some species of porcupinefish, the boxfish is also armed with chemical defenses. It is perhaps no surprise then, that many species of both pufferfish and boxfish sport bright coloration as a passive aggressive warning to would-be diners shopping around the reef for the meal (an evolutionary phenomenon known as “aposematism”, which I outlined in other species very recently). While many species of boxfish are also known for potent differences in the coloration of males and females, both sexes show off conspicuous markings to advertise their toxicity, often consisting of brilliant stripes, reticulations, and spots.

Hey, 1996 called. They want their Rose Art, neon, glow-in-the-dark fuzzy posters back.

So…big deal, right? Lots of things in the ocean are toxic or venomous and have warning coloration; everything from lionfish to sea slugs. What makes boxfish toxicity any different than, say, the toxicity of their close relatives, the pufferfish? The answer comes down to two things; 1) the toxins are completely different and are chemically very unlike almost all other known fish toxins, and 2) the toxins are used in an entirely different way.

Puffers, and most other creatures in the ocean that are endogenously toxic, defend themselves by embedding the compounds in their tissues, right in their very bodies. They saturate themselves with the poison, perhaps taking on a foul taste and/or sickening whatever animals are foolhardy enough to take a bite. But boxfish, when alarmed or actively being eaten, secrete their own toxin in a slimy mucus that oozes from specialized skin cells all over the fish’s body. The clear, toxic snot immediately disperses into the water column, creating an invisible cloud of death surrounding and trailing a very spooked little boxfish.

The force field of chemical ruination unleashed by the boxfish is well-recognized by tropical aquarium hobbyists, many of whom have learned the hard way about the potential consequences of raising these animals alongside other unsuspecting fish. The moment one of Boxie’s tankmates gets little too touchy-feely, the “oh shit danger danger danger!” trigger gets pressed and all hell breaks lose. The boxfish promptly sploogies out a coating of poison goo, and the stuff silently billows out, spreading throughout the tank insidiously and, initially, imperceptibly… a fart in an elevator. It isn’t long until the effects of the toxin start choking out just about every susceptible living critter in the vicinity. Under normal conditions, the toxin is released in the vastness of the ocean, with all its currents and fluid mixing, where the toxin eventually is diluted to the point of being functionally benign. But in the tiny, closed system of an aquarium, the lethal excretion becomes trapped in a small volume, creating an aquatic Dutch oven effect. There is no escape from the concentrated, toxin-infused waters, relative exposure continues to climb, and soon everything in the tank that is vulnerable goes belly up, like roaches trapped in a tented, bug bombed house. I’ve personally heard stories from aquarium owners who have come home to a watery, glass graveyard of floating Nemos…and a single boxfish quivering under a ledge of fake coral, hangdog expression betraying its role in that afternoon’s pescicide.

“Rubik! Bad fish! You stay in your rock hole and think about what you’ve done!”

So what is it, exactly, about those nasty, mysterious, skin residues that would allow such a creature to evade predation in the wild…as well as inadvertently nuke an entire tank in captivity, wiping it clean of all complex life? How does this chemical weapon actually do its job?

The secret of how pahutoxin (what we’ve so far identified as the chief toxin in the mucus secretions, also known as “ostracitoxin”) actually moves itself from the surface of the skin, into the water column, and into places on other animals where it manages to screw things up royally, lies in its basic chemistry. Pahutoxin is a type of chemical compound known as a “surfactant.” Without getting into too much detail about how surfactants work at the chemical level, the general gist is that these compounds are often quite good at 1) dispersing in water and 2) making certain things that don’t dissolve in water suddenly very good at dissolving in water. A good example of a surfactant that you and I use (hopefully) every day is soap, or pretty much any other detergent, for that matter. Soap works by way of a number of chemical properties that allow it to make globules (called “micelles”) around the oils in grime and dirt, which normally repel water molecules and do not mix with good ol’ H2O worth a damn. The detergent effect of soaps comes down to the capacity to “cage” microscopic bits of insoluble grossness in tiny bubble-like formations, allowing it to be washed off whatever surface you want with the addition of water.

And just like how running water easily washes away the soap-and-filth slurry from formerly dirty hands, the ocean’s water readily spreads pahutoxin out and away from whatever boxfish is currently shitting its tiny, vibrantly-colored pants, and right into the mug of the hungry, predatory, and now very unlucky pursuer. It’s also worth noting that nothing about the general appearance of the pahutoxin-saturated mucus conceals the fact that it behaves similarly to detergents. I’ve seen on numerous occasions extraordinarily unhappy boxfish pulled out of the water, decorated so heavily with sudsy mucus that they look like they were just scrubbed down with fucking Dawn. It also comes as no surprise to me that while pahutoxin is certainly a unique chemical among fish (as far as we know), it’s thought to behave similarly to a group of toxins described in sea cucumbers, which are, chemically, “saponins”…which are distinctly known for tending to create lots of bubbles and suds.

So, surfactants are specifically good at breaking up things made of oils, fats, and waxes…things that aren’t normally soluble in water. The membranes that make up the barriers that keep the innards of animal cells nice and contained? They’re, conveniently, made out of a bilayer of lipids (a group of molecules that contain fats, waxes, a lot of fat-soluble vitamins, etc.), and are therefore theoretically susceptible to a surfactant’s detergent properties. It was thought for a long time that detergent properties of pahutoxin on the cell membranes themselves was the primary way in which the toxin hurt aspiring attackers. But studies in the last decade or so have hinted at a far more nuanced and complex mechanism of action in pahutoxin, where there may be very specific sites on the gill membrane cells of fish where this toxin binds….sites that are not shared by relatively pahutoxin-resistant boxfish, explaining, in part, the reported, temporary resistance to the toxin’s deleterious effects among boxfish.

And what, exactly, are these effects? They are…well…pernicious, to say the least.
Pahutoxin has an effect that what we would call “hemolytic”, meaning that the toxin tends to pop red blood cells like goddamn water balloons (“hemo” referring to blood, “lysis” referring to rupturing). Given that there seems to be particularly potent effect on the gill tissue of “enemy” fish, a region where there’s a lot of blood vessels and very important exchange of oxygen and carbon dioxide going down, all of which is necessary for a fish to, you know, not immediately die…this makes a lot of sense as a good way to keep big, ravenous fish from doing what they love to do…eat small fish like boxfish. Although pahutoxin appears to have evolved to specifically combat gilled predators like sharks or groupers, adverse effects from the toxin have been reported in mammals in laboratory experiments, and there are reports of severe poisoning in humans who attempted to eat cooked boxfish. But, the main mechanism appears to be one honed by evolution to disperse widely and make its way into the vulnerable gills of an unfortunate meal-seeker, where it promptly takes to exploding life-giving red blood cells left and right, incrementally cutting off oxygen from reaching the rest of the fish’s body. If the attacker can promptly leave this smog of death, it suffers lasting, irreversible effects, but can potentially live. If the predator tries to eat the boxfish, or is trapped in a tank with one releasing its toxins, the pahutoxin’s effects overwhelm the ability to take in oxygen, and before long, the unfortunate creature meets its end at the hands of agonizing asphyxiation…all at a concentration in the water as low as only 10 parts per million. For some visualization on just how impressively potent this is, consider that a concentration of 10 ppm can be reached by squeezing several drops from an eyedropper into a keg of beer. Spitting out a modest swish of mouthwash into a 660,000 gallon, Olympic-size swimming pool also achieves a 10 ppm concentration.

This is the face of a killer.

It’s also possible that boxfish don’t even make the toxin themselves. It’s may be that they “contract” it out to special bacteria that they harbor in the skin cells that make the poisonous mucus. It wouldn’t be all that unusual, considering that they are so closely related to pufferfish, which have shown on numerous occasions, and in multiple types of tissues, that they contain bacteria (most notably Vibrio) which just so happen to manufacture their famously deadly tetrodotoxin (TTX), and are likely the primary source of this toxin in these fish; an amazing symbiosis of “house me in your body, and I’ll help obliterate anything that tries to eat you…I mean “us”, right buddy?”. A species of Vibrio has been found in the mucus-producing cells of at least one species of boxfish, but at this point, it’s not clear whether this toxin, very different from the more famous, and dangerous, TTX, is actually being produced by the bacteria.

Either way, boxfish are remarkable fish, and have…cornered…the market on a particular method of chemically defending themselves. This method, which has more in common with the acrid sprays of landlubbing skunks than with anything fish in our oceans have evolved, is truly unique.

It’s important to note that while we may not yet completely understand how pahutoxin works, we should acknowledge that pollution of our oceans with compounds that chemically mimic the ways in which pahutoxin interacts with cells and specific binding sites…specifically detergent pollutants like soaps, which can accumulate in coral reef habitats from nearby human habitation and subsequent waste runoff…has the potential to disrupt the way these chemicals normally interact. Detergent pollutants in the environment may block receptor sites for pahutoxin…or yet undiscovered surfactant chemicals in our oceans…and restrict the effectiveness of the toxin in a natural, anti-predator setting. If pahutoxin can’t do its job, then that puts boxfish, or other organisms that depend on natively-produced surfactants working like they had evolved to, at a greater risk of increased exploitation by predators, and eventual population decline.

Image credits: introduction image, very colorful boxfish with yellow spots (Ostracion meleagris), hiding boxfish (credit Christie Wilcox), yellow boxfish (Ostracion cubicus)

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2014. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.