Mesmerizing Marine Mimics: Sea Slug Style

This post is the third in a six post series outlining the evolution of mimicry within the ocean realm. These posts detail various ways in which organisms may copy other organisms in appearance and behavior, and the evolutionary context for how these mimic-model pairings have come to be. The first entry in this series goes over some fundamental introductory concepts and definitions regarding mimicry in general.

The previous entry in this series tackled fish that masqueraded as their flippity-floppity boneless distant cousins, generally to keep themselves from getting devoured by one of the endless multitudes of hungry mouths that tirelessly dart back and forth underneath the waves. The entry before that looked at fish that mimic other fish as part of the same evolutionary strategy. It’s worth mentioning that while I really like fish (I study the things, for Christ’s sake), not every bit of mimicry in the ocean involves gills and fins. Plenty of invertebrates (the perhaps less-than-charismatic things like worms and mollusks) in the oceans also engage in mimicry of other species. Sometimes, just like in the last entry, these imitations can jump across to completely different phyla (a major organizational grouping of life right below “kingdom” (like the animal kingdom, Animalia) and above “class” (like Mammalia, which includes mammals within the phylum Chordata)). It’s also important to consider that the phylum to which all vertebrates belong, Chordata, is just one grouping compared to a shitload of so-called “invertebrate” phyla…like thirty of them (the exact number depends on who you talk to…there’s plenty of taxonomic/phylogenetic disagreement to go around). Familiar, cute vertebrate critters like pandas and cats and goldfish and parakeets get a lot of attention, but in reality they make up a tiny sliver of animal diversity. The vast majority of the animal species on planet Earth are “invertebrates”…a commonly thrown out figure is something like 97% of all animals. In light of this, focusing specifically on some gooshy guys for one entry in this series seems only fair. I guess you say I’m…throwing them a bone….or something.

One group of invertebrates that is deserving of focus in the context of marine mimicry are the nudibranchs (pronounced “noo-dee braynks”). Their name means “naked gill”, which refers to their unique respiratory system. While they are regularly referred to as “sea slugs”, nudibranchs represent just one large taxonomic group of marine-living “slug” (the other groups include things like the solar-powered sacoglossans, a member of which is the “sea sheep” that everyone was losing their shit about a month or two ago, or the huge, ink-squirting sea hare, which is part of lineage distinct from nudibranchs). To reduce confusion on what variety of sea slug one is talking about, many folks refer to them by the shorthand “nudis” (pronounced like one would for “nudies”…although taking care to distinguish between things like “nudi photographs” and “nudie photographs” in casual conversation is STRONGLY RECOMMENDED).

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Mesmerizing Marine Mimics: Fooling Across Phyla

This post is the second in a six post series outlining the evolution of mimicry within the ocean realm. These posts detail various ways in which organisms may copy other organisms in appearance and behavior, and the evolutionary context for how these mimic-model pairings have come to be. The first entry in this series goes over some fundamental introductory concepts and definitions regarding mimicry in general.

A fish that has evolved to mimic a completely different, potentially entirely unrelated species of fish is relatively impressive. It is a testament to the power of natural selection, this honing and whittling down of a creature so that it may converge on the same exact external form for the sake of protection or the easy procurement of food.

But fish all have the same overall “blueprint.” Paired fins, vertically oriented tail fin, eyes in the front, big, snappy mouth, gills behind the eyes, generally sleek and muscular…there are a number of distinctly “fishy” features that evolution doesn’t fuck around with too much. This sort of basic body plan of a taxonomic group is sometimes down as a “bauplan” and its sort of the generic physical shape and scaffolding with which a given lineage of organisms ends up modifying as different branches break off and try out different tweaks and strategies. The “bauplan” for a motor vehicle, for example, is basically four wheels with tires, a broad cabin for passengers resting atop the rolling chassis, windows, engine, headlights, perhaps a trunk in the back. Anyone can tell you that there are many differences between a Chevy Camaro, a Subaru Outback, and a Hummer, but all of them are superficial when you consider the motor vehicle bauplan they all share. Similarly, the alterations and adaptations associated with the evolution of mimicry in these fish are limited by the constraints generated by their overall body plans. A fish can only fake it so far, and imitating another animal with the same bauplan is completely within any developmental constraints.

But there are fish that manage to step outside the “vertebrate box” when it comes to pulling a fast one on their ocean community. There are some fish that are mimics of invertebrates; spineless, squishy, squirmy things that they haven’t shared a common ancestor with for well over 550 million years. These fish convincingly pass themselves off as things that aren’t even remotely built the same way, all through some clever innovation through the prism of evolution.

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Mesmerizing Marine Mimics: Counterfeit Malicious Fish

This post is the first in a six post series outlining the evolution of mimicry within the ocean realm. These posts detail various ways in which organisms may copy other organisms in appearance and behavior, and the evolutionary context for how these mimic-model pairings have come to be.

In the human world, being a “poser” can have serious repercussions.

Well, at least if you are found out by those around you. No one appreciates a fake. A phony. A liar. A disingenuous, duplicitous slimeball. Someone who is, as a notably troglodytic hobbit habitually says, “false.” Someone who appears to portray themselves as something they are not tends to raise the hackles of anyone in their immediate social circle. Sometimes, the issue is a complete breakdown of trust, and an inability for anyone to take your word or feelings seriously. You become an actor. A poor one, one that nobody believes. Sometimes, the transparency of your guise just becomes annoying and exasperating. Like if you saw Little Dragon do a set “at Sasquatch one year” and that was the only time you ever saw them perform, before or since, but now all you do is talk to your friend about how much of a “huge fan” you’ve always been, even though I…I mean your friend…was listening to Machine Dreams back when you were still listening to Jason fucking Mraz like an uncultured jackoff….even though you didn’t know about their collab with Gorillaz, and when asked where they were based, you shat out something about “New York mostly I think.” IT’S GOTHENBURG, FOR FUCK’S SAKE. STOP ACTING LIKE YOU KNOW THINGS, JEFF, BECAUSE YOU DON’T.

….anyways, posers can rub people the wrong way.

But in much of the natural world, faking your way through life may be a great strategy to keep alive and produce lots of offspring. Any trait that gives you in edge in getting food, not becoming food, and making sure you can make lots of babies (which also can get food and not become food) is likely to proliferate in the population. Sometimes, this means using deceit, and looking and behaving like something you are not. When a species resembles another in behavior or appearance (or any other sense), this is known as “mimicry.” The organism that a mimic is imitating is referred to as a “model”, and importantly, mimicry only really works for the mimic if the model is found in the same area. Evolutionary biology is rife with examples, many of which are found in terrestrial ecosystems, and often involve insects…because, partially, there are likely millions of insect species on the planet from which instances of mimicry can evolve. There are swaths of moths that have evolved to resemble wasps, and the moths benefit by fooling predators into thinking they can deliver a painful, venomous sting. European bee orchids have flowers that look very much like the solitary bee Eucera, successfully attracting horny male bees, which then find themselves inadvertently dry-humping a cruel, floral-scented bee blow-up doll, all the while unknowingly satisfying the pollen transportation needs of the orchid. The chicks of the Amazonian cinereous mourner (Laniocera hypopyrra) appear to mimic a fuzzy, rust-colored variety of noxious caterpillar, which helps them not get harassed by hungry wildlife, but at the cost of looking like something that would scamper off the scalp of a particularly controversial 2016 Presidential candidate that shall not be named. These are just a fraction of the examples. In the history of life on Earth, mimicry has evolved over and over again, because, quite simply, it can really pay to pretend to be something you’re not.

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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.

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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!”

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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.

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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.

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Angry Birds, Part 2: Sinister Songbirds

While it is relatively easy to think about massive, belligerent, hook-jawed, feathered monstrosities like the giant petrel, skua, and lammergeier as being kin to the long-extinct therapod dinosaurs, creatures solidly employed in the “flesh-rending-death-beast” profession, perhaps a little harder to grasp is the notion that commonplace little tweety birds have the capacity to be pint-size brutes. But there are certainly some shining star examples that I’ll outline here.

When I refer to “tweety birds”, I mean birds of the order Passeriformes, which are known as the “songbirds.” Robins, sparrows, meadowlarks, finches, orioles, crows, swallows, wrens….everything from Big Bird to Woodstock….Red Robin to the Arizona Cardinals…all of them are passeriform birds. They are members of by far the most diverse order of birds, and with more than 5,000 species, they are among the most speciose of any vertebrate order. They are distinguished from the other groups of birds by, generally speaking, their exquisite control of the syrinx (a vocal organ that is analogous to our own larynx) to generate elaborate bird songs. They are also notable for being a group of animals that has their evolutionary roots placed in a part of the world that is far more frequently noted for having endemic creatures that do not ever leave; Australia and New Guinea. It’s thought that these little guys first broke off from the rest of the flock roughly 50 to 60 million years ago in this arm of the old southern continent of Gondwana (which was isolated then just as it is today) and somehow exploded onto the world stage, rapidly diversifying and eventually finding themselves in all imaginable locations and habitats.

And it is in Australia that the first entry on this list makes its home.

Johnny Two-tone up there (the one who apparently shares an eye-color with Darth Maul) goes by the name of “Australian magpie” (Cracticus tibicen, if you’re nasty), and it’s easy to see why. The black-and-white ensemble (often referred to as a “pied” coloration) and wedge-shaped beak is dead ringer for the magpie bird that many people from the northern continents are familiar with. However, the two birds are not all that closely related, and the pigmentation pattern is a coincidence of convergent evolution. True magpies are in the crow and jay family (Corvidae) and while they are highly-intelligent and mischievous animals, they aren’t particularly aggressive birds, favoring wiley methods of scavenging and hanging around urban and suburban environments for human food waste. In contrast, the Australian “magpie” is a member of the Artamidae family, which is a group of crow-like birds native to the continent and surrounding islands, and the family is far more closely related to other Australasian, Southeast Asian, and Madagascan birds, like vangas and ioras, than they are to the corvids.

It’s also worth mentioning that the genus to which the Australian magpie belongs, Cracticus, is full of birds collectively known as “butcherbirds.”
So, you know we are off to a good start.

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Bioluminescence

Bioluminescence.

One of the more intriguing (at least to me), and beautiful quirks about the evolution of life on this planet is the repeated development of bioluminescence across many different lineages. Bioluminescence is simply the ability of a living organism to produce light. If it’s alive and luminescing, boom, you’ve got an example of a complex chemical cascade that allows sacks of meat not so different from ourselves to light up like a goddamned Christmas tree. Essentially, what is happening with bioluminescence is a highly controlled chemical reaction that releases energy in the form of light emission. This can be done by the beastie itself, or by a symbiotic microorganism that has been acquired by a larger creature. It occurs in multiple kingdoms of life, in terrestrial and marine environments. If I so desired, I could ruminate tearfully on how all of Earth’s life is chemically derived from components forged in a star in a Saganesque exposition of cosmic perspective…and how in some small way, bioluminescence is the means by which stardust can light the darkness of the universe once again. But, heavy-hearted sighs and poetic attribution of consciousness to a mechanically elegant and indifferent universe are for another day, and if done in all seriousness, for another person.

The thing about bioluminescence is that often our understanding of it is limited to a few well-known examples, and without any sort of context, biological or otherwise, other than ‘that is pretty; I like it.’ And while yes, indeed, fireflies and deep-sea fish do have a magical and/or alien quality to them, there is a whole world of bioluminescing organisms that go unloved and underappreciated and denied all the badass reasons for and applications of their abilities. Bioluminescence has evolved many times, and therefore, each example tends to have its own unique story.

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Fungi

Fungi.

Quite possibly the most overlooked of the eukaryotic kingdoms. Not as mobile as their animalian close cousins, and they tend to be more discrete than the giant, showy plants. For most of us, at their best, they are an edible foodstuff, adding a bit of gummy texture to stir-fries. At their worst, they ruin an old strawberry or cause a bit of itchy feet, much to the chagrin of John Madden. They are the completely benign decomposers of the shadows, the wood-rotting, spongey, alien-like denizens of coastal forests and poorly ventilated bathrooms. Soft. Passive. Life’s unassuming and dutiful janitorial crew. Wouldn’t hurt a fly.

Oh.

The unfortunate insects above, now reduced to crumbling husks, were parasitized by a species of Cordyceps fungus. More closely allied with common bread mold than your average forest mushroom, Cordyceps make a decent living out of selectively infiltrating the bodies of various insects, growing inside of them, and eventually killing them and erupting through their exoskeletons. Some can even impact the minds of their insect hosts, making them into little zombies that position their bodies in such a way so that when they succumb to their insides being turned into a palatable slurry, the spore producing fruiting body (or “stroma”) of the fungus can have an advantageous location over the forest below, allowing for the maximum amount of exposure possible to other unwitting victims. Observe below:

Sir David Attenborough’s soothing narration, coupled with the music, make this video far more creepy than necessary. There’s something vaguely nightmarish about those wailing strings and circus-tent music playing alongside images of death-by-killer-fungus. Cordyceps are found worldwide, but enjoy higher density and diversity in the lower latitudes. As far as we know, they tend to go after insects only.

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