On the Origin of Species – Shuckle

In honor of the recent announcement of a re-release of the original Pokemon Gold and Silver, I thought now would be a good time to talk about Second Generation’s most unique addition to the Pokemon roster and one of the most bizarre Pokemon to ever be created. Some of its strange features include acid-secreting feet that can dissolve solid rock, the ability to store and ferment berries in its shell, and for you Pokemon pros out there, the most extreme range of base stats out of all 802 Pokemon. That’s right, this week we’re looking at the Mold Pokemon: Shuckle.

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I can’t tell if Shuckle is happy or angry about being compared to mold (Source: Pokemon Company)

Shuckle can only be described as “really, really weird”. At first glance, it appears to be some kind of turtle, just replace the legs and head with yellow worms and paint the shell a bright red color. While not too out of the ordinary in the Pokemon world, things get a little weirder once you start looking into Shuckle’s biology and realize that the shell it resides in isn’t even part of the Pokemon. It’s actually a rock that’s been carved into a home using secretions from Shuckle’s feet. Now, the ability to break down solid rock is no small feat: not only would Shuckle have to be producing acids strong enough to dissolve the rock, but it’d also need to avoid dissolving itself in the process. This isn’t some made up fantasy ability, however, because there are plenty of organisms in the real world that are able to do just that.

These organisms, called lithotrophs (literally “rock-eaters”), have evolved to use inorganic substances such as sulfides, ammonia, and even certain metals such as iron and manganese. These substances are then used to fuel growth, converting CO2 into more useable forms, much like plants do during photosynthesis. Most lithotrophs are either bacteria, archaea, or fungi, and while they are easily overlooked, many species are an important part of weathering, the process of transforming rocks into soil that can be used by plants. Shuckle is based on one of the most interesting groups of lithotrophs: the endoliths. Unlike most lithotrophs, which can live practically anywhere on earth, endoliths live their entire lives inside of rocks and stone.

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Left: Green and blue endolithic lichens growing in antarctic sandstone (Source: NASA) Right: Endolithic bacteria found in rock samples almost 3 km below the earth’s surface (Source: US Department of Energy – Subsurface Microbe Collection)

Now, life inside a rock is far from easy. For example, rocks are notoriously hard to penetrate, meaning that resources typically required for life are incredibly scarce. For endoliths found close to the surface, cracks in the rocks can allow small amounts of water, oxygen, and carbon dioxide to reach them. Species found in deeper areas, such as bedrock or in rock below the ocean floor, these resources are almost impossible to acquire, which leads to incredibly slow growth. In fact, one species grows so slowly that it can only reproduce once every 10,000 years*.

Shuckle, however, overcomes some of these issues. You see, rather than gathering minerals from the rocks it bores into, the rock is only used for protection while it chows down on its main food source: berries and berry juice. Berries that are stored in Shuckle’s rocky shell mix with the same fluids used to burrow through rock, fermenting into an apparently delicious juice. Unsurprisingly, fermentation is most common in fungi and bacteria**, with the most obvious example being yeast, which is used to make beer, wine, whiskey, vodka, and pretty much any other alcoholic drink.

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Cracking open a cold one with the boys (Source: Pokemon Company)

Believe it or not, alcohol isn’t a vice unique to humans, as many animals have been shown to consume alcohol (usually in the form of rotting fruit) and even get drunk. For example, in places such as Sweden and Alaska, moose commonly eat rotting apples during the fall and end up causing quite a ruckus. In fact, the famous astronomer Tycho Brahe had a pet moose that he would give beer to during parties. Sadly, the moose died one night after having a bit too much to drink and tumbling down a flight of stairs.

Other common animal alcoholics include monkeys and chimpanzees, which are actually used to study a wide range of behaviors related to alcohol consumption. Fruit flies have also been shown to enjoy a bit of drinking, especially male flies that haven’t yet had a chance to mate. For some species, such as fruit bats and tree shrews, alcohol exposure is so common that they’ve evolved incredibly high tolerances to alcohol, to the point where they could easily drink the main cast of Animal House under the table.

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The face of a true party animal (Source: Hement Kumar)

Before I finish, I’d like to touch on one last interesting detail in Shuckle’s design. I believe that Shuckle’s meteor-like shell, combined with its bacterial origin, is a subtle reference to Panspermia, a hypothesis that attempts to explain how life on Earth began. Essentially, Panspermia says that life came to Earth in the form of bacterial spores (a dormant form of bacteria that can survive in extreme conditions), which were carried on or inside meteorites that broke off of planets already inhabited by life.

There are a few potential origins of life in the Pokemon world, including Mew, which is described as being the ancestor of all other Pokemon, and Arceus, which is described as making the universe with its 1,000 hands. While Panspermia may not be an explanation for the origin of life (the bacteria still have to come from somewhere), it’s fun to imagine a very confused Shuckle floating through space on its way to spread life across the stars.

 

Footnotes

* For comparison, the average time between bouts of reproduction for E. coli is about 30 minutes, and the invention of agriculture (one of the key inventions that allowed for the rise of human civilization) is believed to have occurred about 12,000 to 14,500 years ago.

**I’m specifically referring to ethanol fermentation, where sugars are broken down into ethanol and carbon dioxide. Another form, called lactic acid fermentation, occurs in human and animal muscles when they are worked for long periods of time and run out of oxygen.

On the Origin of Species – Starly and Staravia

This week’s Pokemon, Starly and Staravia*, were chosen because of something that I’ve been noticing for the past few weeks: there are a lot of birds chirping despite it being the dead of winter. Now, birds in winter is nothing new to me, but I don’t remember winter birds around my hometown being nearly as vocal as the birds I’ve been seeing around Camden. A few days ago I took some time to ID the birds, and was surprised to learn that they were European Starlings, an invasive bird which has some unusual behaviors and an even more unusual story behind their invasion.

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The winter plumage of the European Starling (Source: Seth Reams)

Before I dive in, I want to point out that the Starly family isn’t based off the European Starling in particular. The starling family Sturnidae (based off Sturnus, the Latin name for starlings) has about 120 different species. I chose the European Starling to focus on because it’s the one that I see almost every day and it’s a pretty interesting bird. Bulbapedia (the Pokemon Wiki I use when writing these posts) suggests that the main inspiration is the White-cheeked Starling, which is native to East Asia and looks a lot more like Starly than a European Starling. That being said, the behavior I’m going to be talking about is found in most if not all starlings, including the White-cheeked Starling.

The most interesting behavior that starlings display is their flocking behavior. Flocking is nothing new, especially in the world of birds, but the flocking in European Starlings is somewhat different. Starlings flock in what are called murmurations, with hundreds to thousands of individuals flying together in some of the most amazing patterns imaginable. Words can’t do murmurations justice, so instead, you should just watch some videos. Seriously, go watch some videos, I’ll wait.

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A murmuration, in case you didn’t click all those links (Source: Alpaca Media)

That’s incredible, right? For ornithologists, animal behaviorists, and bird watchers alike, murmurations bring up a lot of questions. Why do they all fly in unison like that? What causes the mesmerizing undulations of the flock? The first one is fairly easy. Many birds flock together in order to avoid predators**, with the basic idea being: more eyes, more chances to spot the predator, less likely to be eaten. In European Starlings, these predators are typically other birds, like hawks or falcons.

The other question baffled scientists for a long time. There were many hypotheses proposed, including one that suggested the birds were using a “biological radio” (i.e. telepathy) to communicate with one another. Ideas started changing with the rise of computers, which could model interactions between flocking birds. These models assumed a few key rules, namely that individuals will avoid colliding with each other, they will turn if nearby individuals turn, and they will remain in the flock. High speed video later helped to confirm these rules, with changes in direction moving through the flock like ripples from a stone dropped in a still pond.

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Even Staravia is amazed by how complex murmurations are (Source: Pokemon Company)

Sadly, Starly and Staravia flocks are nowhere near as impressive as European Starling murmurations. Both Starly and Staravia are described as being weak and flocking for protection, but only Staravia flocks ever become particularly large (Starly bicker amongst each other in large flocks) but neither seem to have this incredible aerial behavior. In fact, the only other notable description given to Starly and Staravia is that they are quite noisey, something that I can attest to being true in starlings. But even their calls are less interesting than that of European Starlings, which are able to mimic the songs of other birds.

Now, as I pointed out earlier, Starly and Staravia are not based on the European Starling. That being said, while researching the European Starling I learned how it first came to the US, and I’d be remiss if I didn’t talk about it here. You see, you can blame their introduction on the most hated man in high school: William Shakespeare. OK, mabye that’s a bit harsh. The real villain here is Eugene Schieffelin, whose goal was to bring every bird ever mentioned in Shakespeare’s works to America.

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Don’t blame the man, blame the fan

In case you aren’t a scholar on the bard (I’m not going to pretend I am), the European Starling was mentioned in Henry IV Part 1, where a character suggests giving one to King Henry to drive him mad with its constant squawking. That’s right, Eugene decided to bring over the bird that Shakespeare describes as being annoying enough to drive someone insane. Thanks for that.

 

Footnotes

*I’m not including the final evolution, Staraptor, in this week’s post as it’s based off raptors rather than starlings and I want to keep the post a reasonable length.
*This explanation is a bit of a simplification. While it’s true that flocking behavior is useful for avoiding predators, some biologists, such as Frank Heppner, have argued that this added defense doesn’t fully explain murmuration behavior, pointing out that these large flocks are likely attracting predators and that the starlings would be more protected if they perched in nearby trees rather than flocking. Instead, Heppner argues that murmurations are the result of emergent properties, a fancy scientific term for “the whole is greater than the sum of its parts”. Because flocking behaviors are genetically programmed into the individual birds, he argues, flocking becomes inevitable, especially when there are so many individuals in the same place.

On the Origin of Species – Volbeat and Illumise

Valentine’s Day: a holiday dedicated to the celebration of love between people, a day where romantics shower their significant other with gifts of flowers and chocolate, or take them out to a fancy restaurant for a delicious meal. Then there’s people like me, who spend Valentine’s Day hastily photoshopping celebrities or video game characters on to pink backgrounds before adding a bad pun and sending them to my friends over Facebook. In celebration, I’m going to talk about Pokemon’s official lovebugs, Volbeat and Illumise.

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Feel free to send this to your friends. Especially the ones who don’t play Pokemon.

Volbeat and Illumise are based off fireflies, a family of beetles (not flies) most known for their ability to flash a specialized organ found at the end of their abdomen. Fireflies flash their bioluminescent rump by mixing oxygen with an enzyme called luciferase, which breaks down luciferin and releases light. This flashing has a few uses, but the most common one is finding a mate. Males flash their rear ends in set rhythmic patterns that differ between species. Females of the same species are able to recognize these patterns, and will respond to a potential mate with a flash of their own.

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A firefly mid-flight (Source: Terry Priest)

Interestingly, the male fireflies greatly outnumber the females, meaning that most of the males flashing their behinds are never going to get a chance to mate. Females are incredibly selective about which males they respond to, choosing only to respond to males that either flash faster or longer than other males, depending on the species. In the Pokemon world, male Volbeat take this rhythmic flashing a few steps above and beyond fireflies, working together with other Volbeat to create geometric patterns in the sky as directed by female Illumise.

To direct their Volbeat suitors, Illumise use pheromones, specialized chemicals that are used for communicating. Pheromones can be found in a wide range of animals, and are typically used to communicate through an animal’s sense of smell. One well-known example of animals that use pheromones are dogs, which urinate on objects such as trees or fire hydrants to mark their territory. Other animals, such as ants, will use pheromones to mark trails for other members of their colony to follow to food sources. In the case of Illumise, the pheromones are being used to attract potential mates, a common tactic for many insects, including some fireflies.

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Crazy antennae like these are used to detect tiny amounts of pheromones in the air  (Source: Bernardo Segura)

While fireflies may not make as intricate patterns in the sky as their Pokemon counterparts, firefly bioluminescence is pretty spectacular. Fireflies are very efficient when it comes to producing light, with 96% of the energy produced by the breakdown of luciferin being emitted as light. For comparison, fluorescent lights are about 40% efficient, with the rest of the energy being wasted as heat.

One of the major factors that allow fireflies to be so efficient is the structure of the exoskeleton covering their light-emitting organ. Light moves at different speeds depending on what it is travelling through, which causes the light to bend slightly. This property is called refraction, and is the reason the sky is blue, rainbows exist, and glasses work. For fireflies, however, refraction is a problem, as light passing through the abdomen of the firefly can bend and become trapped inside the exoskeleton (and ultimately converted to heat) rather than passing through and reaching a potential mate. To counter this, fireflies have evolved complex microscopic structures that reduce the effect of refraction, ensuring that the maximum amount of light possible can escape their bodies. Scientists are even replicating the structures in OLEDs, resulting in a 55% increase in thee light’s efficiency.

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Shingle-like structures that help reduce refraction (Source: Bay et al. 2013)

While I typically equate fireflies with warm summer evenings, watching them flicker across a field after the sun goes down, I find that Volbeat and Illumise are better fit into Valentine’s Day than summer. Maybe it’s because of their Valentine themed colors, maybe it’s because they were intended to be a pair (they were introduced at the same time the idea of double-battles were added),  or maybe it’s because their main goal is to find each other and light up the night together. Have a good Valentine’s Day.

 

Bonus Info:

There are some species of fireflies where the females will respond to the flashes of males from other species so they can capture and devour them. They do this in order to steal defensive chemicals known as lucibufagins, which they are unable to produce themselves. These chemicals are useful for repelling potential predators such as spiders and birds, as well as protecting their eggs. This behavior isn’t found in Volbeat or Illumise, but it’s too interesting to leave out of the post.

On the Origin of Species – Inkay and Malamar

Determining what animals inspired a Pokemon can be difficult at times. For some, the inspiration is obvious: Ponyta is a horse, Ledyba is a ladybird, Beartic is a polar bear, and so on and so forth. Others can be quite tricky to nail down, either because they’re based off a fairly obscure animal, like the Sea Angel Manaphy is based on, or they’re an amalgamation of several different animals, like last week’s Eelektross. However, even fairly obvious Pokemon can have some hidden inspirations, something I realized while researching this week’s Pokemon: Inkay and Malamar.

As I’m sure you already know, Inkay and Malamar are based off cephalopods, specifically squids and cuttlefish. Cephalopods are nothing new to the Pokemon world (the first one, Omanyte, dates back to Red, Blue, and Green) but until Inkay and Malamar, none of them took advantage of the most interesting aspect of cephalopod biology: the ability to change the color and pattern of their skin.

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Cephalopods, like this Reef Squid, are able to alter their skin to create brilliant colors and patterns (Source: Betty Wills, Wikimedia Commons)

Cephalopods use several specialized organs on the surface of their skin to control the color of their skin. The first type are called chromatophores, and are essentially sacs of red, yellow, brown, or black pigments that can be expanded or contracted to change the color of the surface of the skin. The next type are called iridophores, and are used to reflect light. When used alongside chromatophores, iridophores are able to produce blues, greens, silvers, and golds. The third type are called leucophores, and can be used to reflect any colors found in the environment. Leucophores are especially useful for camouflage, a common tactic used by cephalopods to hide in plain sight while waiting for potential prey.

Although Inkay and Malamar are never described as using camouflage to hide from their prey (their tactics are far more devious), this behavior was vaguely referenced in the Pokemon TV show. In the episode Heroes – Friends and Faux Alike, Team Rocket comes up with the genius plan to disguise themselves as the main characters of the show, Ash, Serena, and Bonnie. They also decide to dress up their Inkay as Ash’s Pikachu, which is one of the most ridiculous things I’ve ever seen in Pokemon.

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There’s no such thing as perfect Pokemo- (Source: Pokemon Company)

Besides camouflage, cephalopods have evolved many different ways to use their color-changing abilities. For example, the Humboldt Squid is believed to communicate with other squid by rapidly switching the color of its skin between red and white (warning: the start of the linked video is kinda terrifying, skip to about 1:10 to see the flashing behavior). While scientists have yet to figure out what these squid are communicating while flashing at each other, the flashing patterns can be sped up or slowed down, suggesting that it may communicate a number of different messages.

Another use for color-changing skin is for hypnotizing prey, a tactic used by the Broadclub Cuttlefish. Upon locating a potential meal, the Broadclub Cuttlefish will spread out and begin flashing a strobe pattern across its body. This pattern seems to dazzle their prey, causing them to stand motionless while the cuttlefish moves in for a quick meal. This nefarious tactic is employed by Inkay to “drain its opponent’s will to fight” and by Malamar, who is described as wielding “the most hypnotic powers of any Pokemon” and “forces others to do whatever it wants”. This ability isn’t to be taken lightly, either, as not one but TWO episodes of the Pokemon TV show revolve around a Malamar trying to conquer the world with its powers.

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“Just keep staring at my tentacles. Now, sleeeep” (Source: PBS Nova)

Interestingly, Inkay and Malamar’s ability to change color seems to be restricted to a series of spots along their body, a design choice that may be functional (much easier to just have flashing lights than to have the entire body change colors) or could be a reference to a number of undersea creatures, such as the Bioluminescent Octopus, which uses modified suckers to produce flashes of light in order to attract prey.

Personally, I believe the rows of lights are based off the comb jelly, a group of very primitive animals in the phylum Ctenophora. Despite the name, comb jellies are not in the same group as jellyfish, but share many of the same characteristics. Both are fairly simple creatures, riding the currents of the oceans and catching any prey that happen to swim into their tentacles. In jellyfish, these tentacles are lined with stinging cells called nematocysts which paralyze their prey, while comb jelly tentacles use sticky cells called colloblasts to tangle up their prey.

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The comb jelly, shown here flashing the camera (Source: George Grall, National Geographic)

One major difference between jellyfish and comb jellies is  their life cycle. Comb jellies have a fairly simple life cycle: the males and females release their sperm and eggs into the water where they mix and form zygotes which turn into baby comb jellies that are just smaller versions of their parents. Jellyfish, on the other hand, have a life cycle with two separate stages: a free-floating medusa stage (e.g. a typical jellyfish) and a non-moving polyp stage (e.g., a sea anemone, a close relative of jellyfish). Polyps, essentially baby jellyfish, will attach to rocks and collect anything that happens to drift nearby. After the polyp has grown, it will produce several “buds” called strobila which break away from the polyp and grow into the typical jellyfish shape we know and love.

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The polyp of a Moon Jellyfish and three of its Pokemon cousins (Source Left: Hans De Blauwe, Right: Pokemon Company)

This brings me to another aspect of Inkay and Malamar’s biology that I haven’t talked about yet: their method of evolving. In the games, Inkay can only evolve into Malamar when you hold your 3DS upside down (how this translates in-universe is unclear, as it isn’t shown in the TV show). This method of flipping Inkay upside down in order to evolve it seems like a clever reference to the life cycle of a jellyfish, albeit in reverse, as the polyp stage (Malamar) should be evolve into the medusa stage (Inkay) if they were following the life cycle precisely.

So why does the polyp stage come after the medusa in Inkay and Malamar? There could be a number of reasons. Maybe it’s easier to have a cute Pokemon evolve into a sinister-looking Pokemon if the second stage is upside down. Or, maybe they aren’t taking this behavior from jellyfish at all, and there’s a type of squid or cuttlefish out there that walks around on their heads that I didn’t find when I was researching. If it’s the second one, let me know, OK?

On the Origin of Species – Tynamo, Eelektrik, and Eelektross

What if I were to tell you that there is a fish out there, in the real world, capable of not only producing a powerful electric shock, but also survives by draining blood from its prey? Now, what if I told you that it was capable of crawling out of the water and living on dry land for several days while it hunts for new victims?

Well, you’d have every right to call me a big fat liar. There isn’t any single species of fish (at least that I’m aware of) that can do all of those things. There is, however, a Pokemon that fits this description, and its name is Eelektross. Unlike last week’s Pokemon, which was based off of a single animal, Eelektross and its earlier forms Eelektrik and Tynamo are based off a wide range of real life creatures, all mixed into what could be considered terrifying if not for the charming Pokemon art style.

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Look at this face. How can anyone hate this face? (Source: Pokemon Company)

The Eelektross family is inspired by a number of animals, but the most obvious is the electric eel*. Electric eels are native to the Amazon River Basin in South America, where they hunt for fish, amphibians, and on rare occasions birds or even small mammals. The most well known feature of the electric eel is their ability to generate up to 600 volts of electricity (for comparison, the typical electrical outlet in your home supplies a meager 120 volts).

This voltage is created using three sets of organs along the length of the fish’s body: the Main organ, the Hunter’s organ, and the Sach’s organ, which together make up around 80% of the electric eel’s body. These organs contain thousands of specialized cells which store a small amount of electrical charge until the electric eel finds some prey. By discharging a few key cells, the electric eel is able to create a small current within its body, which cause nearby cells to rapidly discharge. This discharge causes more cells to discharge, and in a matter of milliseconds, the current flows through the electric eel’s body and blasts their prey, stunning it long enough for the eel to chow down.

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Electric eels: only slightly less adorable than their Pokemon counterparts (Source: Norbert Wu, National Geographic)

Now that the whole “launching bolts of electricity” aspect of the Eelektross family is out of the way, why don’t we move on to the somewhat less charming inspirations for this Pokemon. Namely, the shape of their mouths, which they borrow from one of the oldest living groups of fish: the lamprey. Lampreys are one of the few surviving groups of fish belonging to the superclass Agnatha, which are most notable for lacking jaws. Instead, lampreys have a round, sucker-like mouth lined with small teeth. These teeth are used to latch on to other fish so that the lamprey can feast on its blood.

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Certainly not the most cuddly fish in the sea (Source: Encyclopedia Britannica)

While there isn’t any specific reference of Eelektross or its family consuming blood, they are noted as having very large appetites, and Eelektross in particular is described as pulling itself out of the ocean in order to capture prey. There’s quite a few groups of fish that can survive on land, but the inspiration here is most likely the mudskipper, a fish with sizeable, almost leg-like pectoral fins. Mudskippers are native to intertidal zones around the Indo-Pacific, hopping along the shores at low tide looking for worms, insects, and crustaceans to eat.

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Mudskippers storming the beach (Source: Jon Robson)

The ability to walk on land isn’t the only interesting adaptation mudskippers have at their disposal. Unlike their underwater relatives, which are able to catch prey simply by taking a big gulp of water and sucking in the prey along with it, mudskippers have to catch their prey in their mouths, which they accomplish using what’s called a hydrodynamic tongue. Before going on land, the mudskipper will take in a gulp of water and hold onto it until they find some prey. As they open their mouth to consume their prey, the mudskipper quickly spits out this water and immediately sucks it back in. This blast of water acts a lot like the tongue of a frog, catching the prey and moving it into the mudskipper’s mouth, albeit with a much shorter range.

Electric eels, lampreys, and mudskippers are not the only influences on the design of Eelektross and its family. For example, Tynamo’s design is likely based off a juvenile eel called a Leptocephalus, Eelektrik is described as wrapping around its prey much like a snake, and Eelekross’ behavior of climbing on land and dragging prey back to the ocean is suspiciously similar to the Creature from the Black Lagoon.

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The resemblance is uncanny (Source: Pokemon Company, Universal Studios)

Nevertheless, electric eels, lampreys, and mudskippers form the main basis of the Eelektross family, and in our world, would likely be a terrifying beast. Unfortunately for Eelektross, being a fish capable of walking on land and launching bolts of electricity at prey before draining their blood is fairly passe in the Pokemon world, where animals are capable of creating whirlpools just by yawning, or destroying entire mountains during a temper tantrum, or even folding itself into a jet and flying at the speed of sound.

Footnotes

*Electric eels are not actually eels. The term “eel” refers to an order of fish known as Anguilliformes, which are typically long, slender fish with a dorsal fin that runs the length of its body and fuses with the tail fin. They also have sharp teeth and either live their entire lives in the ocean or in the case of freshwater eels (such as those in the family Anguillidae) return to the ocean in order to reproduce. Electric eels, on the other hand, are a species of knifefish, lack a dorsal fin, don’t have teeth, and live their entire lives in freshwater.

On the Origin of Species – Yungoos and Gumshoos

Over the past few weeks, it has become increasingly obvious to me that biology (and science in general) is about to become a much more difficult career choice, and with the inauguration last week, I decided I should go back to blogging. Rather than going back to breaking down scientific papers, I’ve decided it would be way more fun to talk about biology as it relates to video games and pop culture, something no one has ever done before. In honor of our new president, I’m going to talk about Yungoos and Gumshoos, a line of invasive pests introduced in the latest Pokemon games, Sun and Moon.

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This one’s for you, Trumpy boy (Source: Pokemon Company)

For those of you who are unaware, Sun and Moon take place in the tropical Alola region, a close parallel to Hawaii. There are plenty of interesting new Pokemon from this region worth talking about, but Yungoos and Gumshoos are two of my favorites in terms of how they fit into island biology. You see, unlike most Pokemon from this region, the Yungoos family isn’t native to the Alola region. Yungoos are an invasive species, loosely based off the small Asian mongoose. Mongooses (mongeese?) are a family of predators in the feliform suborder, meaning they are closely related to cats, hyenas, and civets. Mongooses are typically found in Africa and Southern Asia, with the small Asian mongoose ranging from Indochina, across northern India and into Iran. Like other mongooses, the small Asian mongoose is a voracious predator that eats insects, birds, lizards, snakes, and rodents.

In their native habitats mongooses are useful for their ability to control the populations of fast-growing rodents, but in an ecosystem that isn’t adapted to the presence of a predator like the mongoose, such as Hawaii or any of the many Caribbean islands where the mongoose has invaded, they can be devastating to the local ecosystem. Mongooses are known to eat many endangered birds, amphibians, and reptiles, with some even eating the unguarded eggs of sea turtles. The worst part about mongooses in Hawaii though? They weren’t accidentally introduced to the environment, they were brought to the islands on purpose.

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Don’t let the face fool you, this mongoose will destroy your island’s ecosystem (Source: Craig Moore)

The story of how mongooses ended up on Hawaii (as well as many other islands throughout the Pacific Ocean and Caribbean Sea) starts with a plant. Sugarcane, to be exact. The production of sugar from sugarcane is believed to have started around 350 AD in India. Due to the high cost of production and processing, as well as the need for a tropical climate, sugarcane production remained in India, China, and the Middle East until the discovery of the New World. The tropical regions of the Caribbean islands and South America were perfect for sugarcane, and sugar production became one of the main driving forces of the slave trade.

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Sugarcane remains an important cash crop in South and Central America (Source: UF IFAS)

Hawaii began sugarcane production in the early 1800s, with the industry booming during the American Civil War due to Union boycotts of Southern-produced sugar. However, the rise of sugarcane also came with a rise in sugarcane pests, specifically rats. Rats were a common problem in sugarcane fields, and during the late 1800s, many islands began importing mongooses as a way to control their populations. Unfortunately, the people importing them never stopped to consider what effects the mongooses would have on the rest of the environment.

Going back to Pokemon, it’s incredible just how similar Yungoos and Gumshoos are to their real world counterpart. Much like the small Asian mongoose, Yungoos was first introduced as a way to control the population of Rattatas in the Alola region, which responded by adapting to urban environments and becoming more active at night. Both Yungoos and mongooses are diurnal, meaning they are active during the day and sleep at night, although there is a slight difference in their sleeping patterns: Yungoos are described as collapsing from exhaustion around dusk and sleeping wherever they fell, while mongooses choose to retreat to their dens at night rather than leave themselves exposed to any potential predators as they sleep.

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The face of ecological disaster (Source: Pokemon Company)

Yungoos are an interesting addition to the Pokemon universe, as to my knowledge it is the only Pokemon expressly described as an invasive species. Many other Pokemon may be invasive species, based on where they commonly occur (for example, Rattatas are likely to be invasive species in a number of regions) but have never been described as invasives within the game’s fiction. Also, whether it was intentional or not, there’s definitely some good social commentary to be made about this vicious animal with a tendency to attack whatever it sees was brought into an environment where it could freely destroy whatever it wanted, and how it looks suspiciously like Donald Trump.

 

Ant-Mimicking Spiders: The Benefits of Having a Bad Disguise

Halloween, one of the few times a year where people are allowed to dress up and perform the mating dance of their favorite spider species. While most people think of costumes as a fun way to show off their creativity or love of monsters, animals, or tv and movie characters, many animals use costumes as a way of staying alive. These costumes can be classified as either camouflage (when an animal is disguised as leaves, tree bark, sticks, or dirt) or mimicry (when an animal is disguised as another animal). A good blog to look at to learn about some of the incredibly diverse forms of camouflage and mimicry found in nature is Not Exactly Rocket Science from Discover Magazine.

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A leaf insect from the family Phylliidae, hiding from predators (Source: McKay Savage)

Batesian mimicry is a form of mimicry where an animal that can easily be eaten by a predator has evolved to look like another animal that is either poisonous if eaten (such as viceroy butterflies that mimic monarch butterflies) or can harm the predator if provoked (such as hoverflies that mimic bees or wasps). Some disguises are incredibly elaborate, such as those found in caterpillars in the genus Hemeroplanes, which can alter the shape of their bodies to resemble snake heads. Since this form of mimicry relies entirely on fooling potential predators, then it should stand to reason that the more a mimic resembles the animal it mimics, the better a chance they will have to survive. However, many species only mimic superficial traits such as coloration, leading scientists to ask: why are there so many inaccurate mimics?

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Hemeroplanes caterpillar mimicking a snake (Source: Dan Janzen)

This question was investigated by a team of researchers from universities in the Czech Republic, Germany, and Australia in the article Is the Evolution of Inaccurate Mimicry a Result of Selection by a Suite of Predators? A Case Study Using Myrmecomorphic Spiders. The paper starts with a run-down of several hypotheses attempting to explain this phenomenon, such as mimics attempting to mimic several model species at once (such as hoverflies mimicking both bees and wasps) or the costs associated with matching the exact shape or size of the model species (some body shapes have reduced space for egg production, which can reduce the number of offspring an individual can produce).

The authors point out that these hypotheses only considers predators that would avoid potentially dangerous prey. If predators prefer to eat the species that the mimics are attempting to resemble, then these mimics have a higher chance of being eaten the more closely they resemble their models. Ant-mimicking spiders such as those in the genus Myrmarachne are almost indistinguishable from ants, which reduces their overall risk of predation but greatly increases their risk of being eaten by ant-eating predators. They suggest that mimics that in order to counteract this change in predation risk, mimics may evolve alternate methods for survival, such as fleeing from certain predators.

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Myrmarachne spider mimicking an ant (Source: Dr. Greg Anderson)

To test these ideas, the authors looked at three species of spiders (Liophrurillus flavitarsis, Phrurolithus festivus, and Micaria sociabilis) that resemble ants. In addition to coloration patterns, these spiders mimic their ant models by lifting their front legs into the air and waving them around in a way that resembles the movement of ant antennae. One of each spider was placed into a container, along with an ant of the species each spider was mimicking and either a predator that preferred spiders (spiders of the genera Palpimanus and Drassodes) or a predator that preferred ants (spiders of the genus Zodarion). The researchers looked at which potential prey each predator attacked as well as how each potential prey responded to the presence of a predator.

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The three spider species being studied, along with the ants they are mimicking. A) Liophrurillus Flavitarsis B) Phrurolithus festivus and C) Micaria sociabilis. (Photo: Pekar & Jarab, 2011)

They found that ant-eating predators attempted to capture both the ants and the ant-mimicking spiders, with greater capture rates when attacking ants, whose response to the predator was to turn towards it and take a defensive pose, than spiders, whose response to predators was to lower their front legs and flee. Conversely, spider-eating predators didn’t attempt to capture ants or ant-mimicking spiders, but would quickly capture other spiders that did not mimic ants. The authors suggest that the form of the spiders not fully replicating the form of the ants being mimicked is a result of a lack of evolutionary pressure. Since they were similar enough to ants to avoid spider-eating predators, there was no reason for the spiders to create a more convincing disguise. The authors suggest that this lack of pressure once mimicry is good enough to fool predators is an important reason for the high amounts of inaccurate mimics, while stressing the importance of looking at the evolution of other mimics in systems containing multiple predators.

This paper emphasizes two major themes of biology that I have become increasingly aware of throughout my college career. The first theme is that evolution only cares about getting an organism to be good enough to survive and reproduce. These spiders have evolved to mimic ants to reduce their predation risk. Once the spiders resembled ants enough to fool their predators, there was no reason to continue evolving to look more like ants. They were good enough to survive, so there was no reason to keep pushing in that direction.

The second theme is that everything in nature is more complicated than it seems at first. Mimicry is generally accepted as being an attempt by organisms to fool predators, which increases their survival. But, as this paper points out, if there are predators that eat the animals being mimicked, then the animals doing the mimicking are still at risk of being eaten. Every part of an ecosystem is linked, and the longer you look at one set of links, the more links you notice.