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Dewgong is NOT a Seal (or a Sea Lion)


A common complaint among certain segments of the Pokémon fandom is that the quality of Pokémon designs has declined since the premier entries of Red and Blue. These folks, dubbed “Genwunners” lament the likes of Vanillish and Honedge for their laziness in concept and uphold the First Generation as the pinnacle of Pokémon design.

Rebuttals have been made against this argument ad nauseum over the years and you can surely find them elsewhere for they are in no short supply. But perhaps no better example of First Generation oversights can be found than the Seal Lion Pokémon, Seel and Dewgong.


From the offset, Seel demonstrates the lack of thought given toward it conception, as its English name literally changes only one letter from that of the animal it quite generously borrows its design from. Its category name in the Pokédex—the Sea Lion Pokémon—is a misnomer too.. Despite having close relatedness and sharing many anatomical features, seals and sea lions are not the same creature. You can easily spot the difference by taking a look at its ears. If you can’t find them, you’re probably looking at a seal, as most “true” seals lack external ear flaps. Ear flaps present? You got yourself a sea lion. From a single glance at Seel it lacks the conspicuous ear flaps of a sea lion. Thus, however lazy its name may be, Seel is indeed a seal.


But at least seals and sea lions are in the same clade, a group organisms who share a single common ancestor. Along with the mighty walrus, seals and sea lions are grouped together in the clade Pinnipedia, pinnipeds for short. Seel would fit in nicely with other “poképinnipeds” such as Spheal (a slightly better name than Seel), Walrein, and the ever lovable Popplio. However, the same cannot be said for Seel’s evolved form, Dewgong, also erroneously categorized as the Sea Lion Pokémon when it is neither seal nor sea lion nor pinniped at all.

Dewgong is a dugong.

Again, such creative names from the First Generation.

If you’ve never heard of a dugong you’re probably more familiar with its close cousin, the manatee. Like manatees, dugongs are marine mammals that spend their entire lives in the water save when they need to breathe. Dugongs are typically found in the coastal waters of the Indian and West Pacific Oceans and graze on seed grasses, earning them and their manatee cousins the name “sea cows”.

These sea cows also have another name, sirenians, derived from stories of early sailors mistaking them for beautiful mermaids after months at sea without women. And who could blame them? Sirenians are majestic creatures.


Basically the same.

But they are not pinnipeds. Not even close.

To understand why, you must learn the history of your mammalian ancestors and how they have made many returns to sea.

Throughout the history of tetrapods (four-footed animals), the return to the water from whence they came is a bit of a “recurrent theme” in their evolution. Ever since Tiktaalik pulled itself onland some 375 million years ago, the water has called us back home (like in Moana!) and many times we have answered the call.

The amphibians never truly cut their ties with the water, but the amniotes—birds, reptiles, and mammals—all have made treks back to the ocean in one form or another. Regarding us mammals, seven groups have transitioned back to water—cetaceans (whales and porpoises), sirenians, pinnipeds, an extinct branch of aquatic mammals known as Desmostylia, as well as polar bears, sea otters, and aquatic sloths.

While the the later lineages still retain most of their terrestrial features, cetaceans, pinnipeds, and sirenians are or are almost entirely aquatic in their lifestyle. Additionally, the rather astute student of biology may recognize many seeming homologies between these three groups such as modification of the forelimbs into flips. And considering that at one point all these animals were once fully terrestrial, one might assume that such a massive evolutionary shift could have only evolved once in the mammalian line. That these marine mammals form a single clade and share a single common ancestor from which they all descended from.

Except, they didn’t.

As best as we can decipher from the fossil record and modern genetics, marine mammals evolved the adaptations for marine life and made the return to water seven separate times.

The three most aquatic groups—Cetacea, Sirenia, and Pinnipedia—are themselves scattered across the mammalian evolutionary tree. Pinnipeds are nested within Carnivora, more closely related to cats and canines than they are sirenians, themselves closer to elephants and aardvarks.


An extremely simplified phylogeny of marine mammals. Blue lines indicate points at which the marine transition evolved. Marsupials are used as the outgroup (represented by Kangaskhan).

For a better perspective of the evolutionary distance between Seel the Seal and Dewgong the Dugong, seals are more related to us than they are to dugongs (specifically, we share a more recent common ancestor with Carnivora as primates than Carnivora does with Afrotheria, the clade which sirenians are nested in).

In essence, when Seel evolves into Dewgong, it jumps branches on the evolutionary tree to an entirely different clade. It would be like if Pikachu evolved into Platypus.

That said, I have no enmity toward Dewgong. In fact, I have a soft spot for the Pokémon even if its name is stupid. We bonded during a playthrough of Pokémon LeafGreen. I traded a Ponyta for him on Cinnabar Island. Seelor was his given name. We swept through the Elite Four and he’s been with me ever since. We now explore the Alola region together. And sure he may not have the most original name or creative design, but those things don’t make me like a Pokémon. It’s the experiences we’ve shared that have solidified Dewgong as one of my personal favorites.

So love your Pokémon, regardless of whether they’re based on keys or cats or clones of previous Pokémon. For aren’t the experiences we share with them more important?

But for the record, Seel and Dewgong are still incredibly lazy names.

Accurate Pokédex Entries

Seel, the Sea Lion Pokémon: Despite being categorized as the “Sea Lion Pokémon” it is actually a seal as its name would suggest.

Dewgong, the Sea Lion Pokémon: Millions of years ago, its ancestors walked on land. Now, Dewgong can be found in oceans everywhere though they prefer colder waters.


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Sources Cited

Uhen, Mark D. 2007. Evolution of Marine Mammals: Back to Sea After 300 Million Years. The Anatomical Record 290:514-522.

Butterfree vs. Cutiefly: Pokémon Competition (and we ain’t talking about battle)


In nature, there are a limited amount of resources and life is in constant pursuit of these resources. It is this pursuit which drives many interactions from predation to parasitism. But, what is a resource?

A resource is anything that is consumed by an organism to grow and maintain its life functions. Food is always a resource, as is water for land-dwelling organisms. However, a resource doesn’t always have to be literally consumed. Space is a vital resource, particularly for sessile, or immobile, organisms. In this instance, space is “consumed” when an organism occupies it and subsequently relinquished upon that individual’s death. Potential habitats such as hollowed logs or abandoned burrows also constitute resources to be consumed.

A resource may be in demand by one species or many species, but regardless only a select number of individuals can consume a resource at a time. When a resource is consumed, its availability to other individuals decreases. This is the crux of competition.


Competition simply describes situations where an individual or group of individuals reduces the availability of a resource to other individuals through either consumption of the shared resource or by directly interfering with other individual’s ability to access the resource.

Organisms compete for a range of shared resources from food, to shelter, to space, and these competitors play by brutal rules—last man standing wins. A far cry from the fictional faints of the Pokémon world…or not.

Just as they compete in battle, Pokémon also compete in nature without the safeguard of trainer referees to steer these confrontations away from more fatal outcomes.

A prime example of this struggle can be found with an unsuspecting duo—Cutiefly and Butterfree. While the Bee Fly and Butterfly Pokémon respectively give the appearance of being nothing more than polite pollinators, the two are engaged in a fierce fight for flowers:

Nectar and pollen are its favorite fare. In fields of flowers, it gets into skirmishes with Butterfree over food. (Cutiefly, Pokémon Ultra Sun)

Nectar from pretty flowers is its favorite food. In fields of flowers, it has heated battles with Cutiefly for territory. (Butterfree, Pokémon Ultra Moon)

This is an excellent example of interspecific competition, when individuals of different species compete for resources. In this case, the resource being competed for is nectar.

Interspecific competition regulates competing populations, often suppressing both from reaching population levels they would otherwise achieve in the absence of competitors. Suppose, a Cutiefly reaches a flower before a Butterfree. The nectar inside is consumed and while nectar is a renewable resource with time, for the time being the availability of nectar for all Cutiefly and Butterfree decreases. But, it is the Cutiefly population which reaps the benefits as another individual can maintain its life processes, ensuring that is population remains up. The inverse is true for the Butterfree population, where another individual is deprived of nectar and thus must seek another nectar source or die, lowering the Butterfree population.


These interactions can lead to situations where one competitor proves better at consuming the shared resource drives the lesser competitor to extinction. This is the competitive exclusion principle.

Coined by Garrett Hardin (1960), the competitive exclusion principle says that if two species are competing for a limited resource, the stronger competitor will drive the weaker to extinction. As put concisely by Hardin, “Complete competitors cannot coexist.”

This principle is derived from the findings of G. F. Gause. He conducted experiments with two species of paramecium, a type of microscopic organism that could live in petri dishes. Grow separately, the paramecium grew rapidly, limited only by the food available to them in their respective dishes. However, when Gause grew them in the same dish with the same amount of food, one species proliferated while the other died out.


Later experiments with other organisms found similar results. Fruit flies, mice, beetles, and plants; in every case only one competitor emerged victorious while the other died out.

Why does this happen?

Simply put, if one organism can more efficiently consume a resource and decrease its availability to its competitor, then the dominant species increases, while the population of the lesser competitor decreases. The gap widens over time, and soon a negative feedback loop forms where the more abundant the dominant competitor becomes, the fewer resources there are available to the ever-dwindling numbers of the lesser competitor, further leading to its population’s decline.

This indirect interference with the competing population is referred to as exploitative competition. But not all competition is conducted indirectly. Sometimes, a species must take matters into its own hands (or fins, claws, leaves, etc.) to ensure they do not end up on the wrong end of the competitive exclusion principle. This is called interference competition, or when direct antagonistic actions are taken against a competitor to procure a resource, or at the very least prevent it from fall into the competitor’s hands (or fins, claws, leaves, etc.). And Cutiefly and Butterfree’s actions are antagonistic to say the least.

Butterfree’s entry in Pokémon Ultra Moon speaks of “heated battles with Cutiefly for territory” and Cutiefly’s Pokémon Ultra Sun entry states “it gets into skirmishes with Butterfree over food” in the flower fields of Alola.


So, if complete competitors cannot coexist, is it only a matter of time until either Butterfree or Cutiefly drive the other to extinction on Alola?

Well, maybe not.

On the offset, Cutiefly appears to be the dominant competitor. It’s Pokémon Sun Pokédex entry says that it can sense auras and thus “identify which flowers are about to bloom.” This alone gives Cutiefly a significant advantage over Butterfree. Being able to visit flowers immediately in bloom not only allows Cutiefly to fulfill its nectar needs before Butterfree but lets Cutiefly avoid direct confrontations with its competitor, who has a literal competitive advantage bearing poisonous scales on its wings which according to its Pokémon Moon entry scatters over Pokémon who attack it. With Poison being a weakness of Fairy-Type Pokémon such as Cutiefly, these encounters could prove fatal for the Bee Fly Pokémon.

Indeed, these Pokémon are “complete competitors,” but they can coexist.

A peaceful coexistence can be achieved through niche partioning, the ecological equivalent of dividing your childhood bedroom in half with your annoying sibling so you do not kill each other. Niche partioning occurs when competing species coexist by either using different resources or continuing to use the shared resource but occupying different habitats either physically or temporally (i.e. are active at different times of the day or during different seasons).

A textbook example of niche partioning comes from a study conducted by Joseph Connell (1961) on two species of barnacle, Balanus and Chthamalus.

The two barnacles lived in the intertidal zone of an ocean cliffside where the shared resource is space. Connell found Balanus barnacles the better competitor, as they had heavier shells to withstand Chthamalus crowding and grew rapidly, faster so than their competitor. Additionally, these feisty crustaceans would edge themselves under Chthamalus shells and pry them from their spots!

How could Chthamalus barnacles persist under such competition? Well, for all their shell-shoving, Balanus were not too keen to dry land, unfortunate for a creature living in the intertidal zone. Thus, they were confined to the lower portions of the cliffside where water had a more constant presence.


However, Chthamalus were desiccation-resistant, and could survive low-tide conditions. So, they colonized the upper portions of the intertidal zone free of competition.

Chthamalus surely could have lived in the lower intertidal zone as well, its fundamental niche consisted of both areas. But competition from Balanus limited it to the upper zones, its realized niche.

Thus, they were able to coexist, in segregation perhaps, but at least no one is shoving anyone off a cliffside.

A similar peace can be achieved between Cutiefly and Butterfree as well.

Like Balanus, Cutiefly may be the dominant competitor with its aura-sensing abilities, but the Pokédex gives no indication that it would be able to gather nectar under rainy conditions. However, Butterfree’s does:

Water-repellent powder on its wings enables it to collect honey, even in the heaviest of rains. (Pokémon Silver Version)

Butterfree could easily harvest nectar during periods of rain in which it wouldn’t have to compete with Cutiefly, or better yet find a realized niche in areas of Alola more prone to rain such as Route 17 or Po Town where Cutiefly couldn’t achieve flight.

Competition is a fact of life, but it does not always have to end in extinction.

Accurate Pokédex Entries

Cutiefly, the Bee Fly Pokémon: Using its aura-sensing abilities, Cutiefly can identify which flowers are about to bloom, allowing them to gather nectar before Butterfree arrive to pester them. The two are engaged in interference competition over nectar.

Butterfree, the Butterfly Pokémon: To avoid competition with Cutiefly, Butterfree tend to cluster in areas where rain is common as their waterproof scales allow them to gather nectar in the heaviest storms. This niche partioning allows them to co-exist peacefully with Cutiefly.

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Works Cited and Further Readings

Connell, Joseph H. 1961. The influence of interspecific competition and other factors on the distribution of the barnacle Chthamalus Stellatus. Ecology 42:710-723.

Hardin, Garrett. 1960. The Competitive Exclusion Principle. Science 131:1292-1297.

Ricklefs, Robert E. 2008. The Economy of Nature. 6th Edition. W.H. Freeman and Company. New York, NY. pp. 328-345.

Mareanie and Toxapex: The Crown-of-Thorns Pokémon (Pokémon Eating Pokémon Part 1)


The sea in many ways is a curious contradiction, as it is simultaneously the womb of life and home to a fierce array of predators. It is both the source nourishment and great cruelty. Hidden underneath its beautiful foaming blue sheets are the most crafty and devious creatures ever to have been seen by men. Swarms of jellyfish dragging their forest of stinging needles through the ocean currents, packs of prehistoric sharks so fine-tuned for predation that they have gone relatively unchanged since their dinosaurs, as is a common theme with nature’s apex predators.

The Pokémon oceans are no safer. In place of jellyfish are hordes of Tentacruel who cause fish to scatter whenever to congregate (1). Sharpedo zip through the water upwards of 75 mph, slicing through hulls of ship and snaring any unfortunate prey in their razor teeth, appropriately earning the title of The Bully of the Sea (2).

But lurking just off the coast of Melemele Island in the Alola region is a particularly devious critter. The waters of Alola are host to a problematic set of predators commonly known as Mareanie and its evolved form, Toxapex. Classified as the Brutal Star Pokémon, Mareanie has an infamous reputation for feasting on Corsola.

It’s found crawling on beaches and seafloors. The coral that grows on Corsola’s head is as good as a five-star banquet to this Pokémon. (Pokémon Moon)

But this predation is not limited to mere words in a Pokédex. The Seventh Generation of Pokémon Games introduced a new mechanic known as SOS battles, in which, a wild Pokémon will call upon an additional “ally” Pokémon to aid it in battle if it’s health drops below 50%.


However, in the case of Corsola, on rare occasion a Mareanie will appear when it calls. But instead of attacking the trainer’s Pokémon, Mareanie will instead attack the very Corsola that called it to battle, in many cases even knocking out the poor Coral Pokémon. Furthermore, to the frustration of many gamers, this is the only way Mareanie can be obtained in the game.

But it terms of sheer brutality, its evolved form, Toxapex, takes the cake:

Toxapex crawls along the ocean floor on its 12 legs. It leaves a trail of Corsola bits scattered in its wake(Pokémon Sun)

Those attacked by Toxapex’s poison will suffer intense pain for three days and three nights. Post recovery, there will be some aftereffects(Pokémon Moon)


Toxapex, the Brutal Star Pokémon

While at first glance, these entries may seem like the typical Pokédex hyperbole, with a few word tweaks these could easily describe the real-life Acanthaster planci—the Crown-of-Thorns starfish.

Most common in the oceans of Australia, though distributed throughout Indo-Pacific waters, the Crown-of-Thorns starfish crawls along the sea floor in search of coral polyps which it primarily feeds on. Like its Alolan counterparts, the Crown-of Thorns starfish is a Poison-Type per say, as it is armed with an arsenal of toxins known as saponins. While we can only speculate on the aftereffects of Toxapex’s poisonous sting, in human, the crown-of-thorns sting can lead to a plethora of symptoms, including swelling around the site of entry, followed by a sharp sting that can last for hours, nausea, and bleeding (9). Indeed, there will be some aftereffects.

Just as Mareanie and Toxapex prey on Corsola, the Crown-of-Thorns starfish preys on coral, which, unlike the Pokémon Corsola, are sessile organisms. Considering how slow most starfish move, this is only to the Crown-of-Thorn’s advantage. Possessing as many as 21 tentacles (3), the starfish attaches itself to living coral colonies where it begins its feeding process. First, the starfish forces its stomach out of its mouth and onto the surface of the coral. It then releases digestive enzymes to break down the coral tissue. As the starfish retracts its stomach, it draws in the broken-down tissues, leaving a scar of white coral skeleton, often referred to as a “feeding scar” (4) .


“Feeding scar” on Australian coral reef from crown-of-thorns starfish.

While not as brutal as Toxapex’s treatment of Corsola, the feeding habits of Acanthaster planci can have deleterious effects on coral colonies and coral reef ecosystems as a whole. Once a feeding scar has formed, surrounding algae will infest the wound, resulting in a crusty skeleton appearance (5). In most cases, the corals—while not in the best aesthetic state—continue to live, though with their vibrancy diminished. However, in this weakened state, some species of coral will crumble due to agitation from storms and other sources of rough waters. Moreover, in addition to invasions by filamentous algae, other organisms such as sponges and “soft corals” will move in on the feeding scars. Gradually, this cascades into an environmental shift in which surfaces where hard coral polyps would take hold are occupied by the invaders. This, in effect, deprives many fish and marine herbivores of their habitat and food sources (6).

Now consider the following PokéDex from Pokémon Sapphire Version:

“Clusters of Corsola congregate in warm seas where they serve as ideal hiding places for smaller Pokémon.” – Pokémon Sapphire Version

Perhaps a similar effect is found in Alola as a result of Mareanie/Toxapex’s predation of Corsola. This would explain Corsola’s rare encounter rate, as well as other Pokémon supposedly endemic to Alola.

Additionally, starfish populations are on the rise. Currently, the exact cause for this spike in population is unknown. Some proposed hypotheses include the depletion of natural predators due to overfishing, rising sea temperatures enhancing the development of larvae, or that simply these observed outbreaks are no more than an aggregate of starfish having previously consumed all adjacent coral colonies and thus cluster together in a single area. Regardless of the cause, the impact of these creatures remains severe, as a study of the Great Barrier Reef revealed that over a 27-year-long period, in a survey of 214 coral reefs, the reef suffered a 50.7% loss of initial coral cover (7). The damage was attributed to three main causes—tropical storms, coral bleaching, and the crown-of-thorns starfish. The starfish alone were responsible for 42% of the total coral loss.

However, there is hope. Recently, researchers have discovered a means of controlling these seemingly invincible organisms. A single, careful, injection of household vinegar into the tentacle of a crown-of-thorns starfish can render the starfish lifeless within 48 hours (8). While the death of any creature—even one that is quite a nuisance—is unfortunate, it is the hope of conservationist and environmental agencies alike that this new treatment will spare the last of the world’s reefs from the wrath of the Crown-O-Thorns.

Perhaps a similar method could be employed on the Mareanie of Alola.

Of course, you would have to find one first.

A suggestion. If you stumble across a Mareanie, don’t faint it, either with Pokémon or your mother’s vinegar.


Accurate Pokédex Entry (Mareanie): In Alola, much of the Corsola loss in recent years can be attributed to a spike in Mareanie populations. However, scientists have found that injections of household vinegar might be used to control their growing population.

Accurate Pokédex Entry (Toxapex): No one knows for sure why its numbers are on the rise. One hypothesis is that overfishing has depleted the oceans of Alola of Toxapex’s natural enemies, allowing the Brutal Star Pokémon to proliferate unchecked, leaving Corsola everywhere scarred and crumbling.


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Works Cited

  1. Game Freak. Pokémon Moon.Nintendo, 2016. Nintendo 3DS.
  2. Game Freak. PokémonSun.Nintendo, 2016. Nintendo 3DS.
  3. Caso, M.J. (1974). “External morphology of Acanthasterplanci (Linnaeus)”. Journal of the Marine Biological Associataion of India16 (1): 83–93.
  4. Current Biology
  5. Belk, D (1975). “An observation of algal colonization on Acropora asperakilled by Acanthaster planci‘.”. Hydrobiologia46 (1): 29–32. doi:10.1007/bf00038724.
  6. Wilson, S K; Dolman, A M; Cheal, A J; Emslie, MJ Pratchett; et al. (2009). “Maintenance of fish diversity on disturbed coral reefs”. Coral reefs28(1): 3–14. doi:10.1007/s00338-008-0431-2.
  7. De’ath, G. et al. 2012. The 27–year decline of coral cover on the Great Barrier Reef and its causes. PNAS109:17995-17999.
  8. Boström-Einarsson, L. & Rivera-Posada, J. Coral Reefs (2016) 35: 223. doi:10.1007/s00338-015-1351-6
  9. Birkelandand Lucas (1990). Acanthaster planci: Major Management Problem of Coral Reefs. CRC Press. pp. 131–132. ISBN 0-8493-6599-6.


Pokémon Eating Pokémon: Do Pokémon Eat Each Other? (Introduction)

Pokemon eating pokemon

“We are not afraid of predators, we’re transfixed by them, prone to weave stories and fables and chatter endlessly about them, because fascination creates preparedness, and preparedness, survival.” – E. O. Wilson

One of the most fundamental relationships in nature is that between predator and prey, otherwise known as predation. In simple terms, predation involves the consumption of one organism (prey) by another (predator). The interactions between predator and prey have fueled an evolutionary arms race, as predation is one of natural selection’s favorite tools for shaping life. The struggle for life has forged the vast biodiversity we see today—from the pyrotechnics of the bombardier beetles, to the assemblage of potent toxins of the Portuguese Man-O-War, to the breakneck dives of the Peregrine Falcon, life continues to push the limits of possibility to fulfill its ultimate biological purpose—to adapt, scatter, and survive.

The mandate of life to propagate itself has led to what many critics of evolutionary theory would consider a dark and grim world, a world governed by the Darwinian aphorism “Survival of the fittest”, a world where this concept is applied in all aspects of life, natural and social. It is with this portrait of the natural world that they postulate a greater purpose, and from that greater purpose they claim it is only reasonable to expect a greater hand guiding these dynamic interactions.

However, to view the dance between predator and prey as an unfortunate side effect of early man’s follies is to ignore the beauty that has arisen from this eternal struggle. For if the day does come when the wolf shall live with the lamb, it will surely herald the demise of life forever. A stagnant ecosystem is a dead ecosystem. The day where packs of wolves no longer chase down lambs will be a sign onto which this grand hand has dealt the final blow to his creation.

Just as the occasional conflagration is needed to clear the overgrown forest, predation and its, at times, heart wrenching cruelty, is necessary for the continuation of life.

As with many aspects of the natural world, this necessity extends onto the fictional universe of Pokémon. As discussed in previous entries, the Pokémon World is no stranger to interspecies interactions. Parasitism is alive and well in Parasect, a Pokémon who upon evolution has its mind and bodily autonomy hijacked by a parasitic mushroom on its back, an obvious illusion to the real-life Corydceps, a genus of fungi most notably featured in the Naughty Dog’s hit game The Last of Us. In Slowbro and Shellder—Mutualism, Commensalism, or Parasitism, I argued that Slowbro benefited from a mutualistic symbiotic relationship with Shellder. Perhaps the most obvious interaction between Pokémon is the trainer-mediated engagement in nonconsequential battle—otherwise known as Pokémon Battles. However, these interactions, for the most part, do not influence the greater ecosystem. Furthermore, all parties involved leave without substantial harm but without significant gain either.

Quite simply, Pokémon battles are ecologically meaningless encounters.

However, when Pokémon engage with each other outside of the mediation of a human-trainer referee, these encounters become far more interesting. The hands of evolution take shape and suddenly trivial encounters hold life and death in the balance, the tools of battle are wielded without restrain as Pokémon fights Pokémon with the intent of either walking away with their life intact or feasting on the corpse of their fallen opponent.

To answer the question posed by the title; yes, Pokémon do eat other Pokémon, though explicit details of these interactions are scarce at best or left in vague ambiguity. For the purposes of this survey, with two notable exceptions, only entries which explicitly cite Poké Predation will be considered a true predator-prey relationship. Indeed, the Pokédex is rife with mentions of Pokémon chasing and consuming an unidentified “prey”, but since the question of whether animals exist in addition to Pokémon in this fictional world is yet unanswered definitively, for the sake of simplicity we will limit our inquiry to those we are sure prey on their fellow Pokémon. But make no mistake, even with this criterion, the Pokédex is abundant yet with tales of fierce predation, many of which have appeared already on numerous creepy Pokédex entries lists. However, this survey of Poké Predators will illuminate new entries and Pokémon precisely skimmed over and deepen our understanding and appreciation for the complexity of this world and our own.

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Should Muk and Grimer be Eradicated?


“A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise.” Aldo Leopold, A Sand County Almanac (1949)

In 1980, the World Health Assembly declared that, after a lengthy global campaign of vaccination and vigilant surveillance, smallpox had been eradicated. No other infectious disease has achieved this distinction, though a few knock at extinction’s door.

Guinea worm is a likely contender. The cause of dracunculiasis—a disease as nasty as its namesake would suggest—Guinea worm afflicted more than 3.5 million people year in the 1980s. However, thanks to the efforts of The Carter Center, World Health Organization (WHO), UNICEF, and many others, incidences of the infection have been dramatically reduced by more than 99%, with only 30 documented cases reported in 2017.

Within our lifetime, Guinea worm is likely to become the second human disease to become eradicated, and the first true organism to have been consciously and intelligently led to extinction.

The human superorganism has set its sights on other targets as well. In 2007, Bill and Melinda Gates caused a stir in philanthropy and medical circles alike when they announced plans to eradicate malaria—an endeavor previously abandoned when mosquito populations evolved resistance to common pesticides such as the now infamous DDT. Malaria-vectoring mosquitoes subsequently bounced back from their dwindling numbers to devastate impoverished African nations. The topic of eradication had since become a fairy tale that would not be fancied, that is until recently. “Theoretically, there’s little doubt that malaria could be eradicated,” writes Leslie Roberts and Martin Enserink for Science magazine, “because there’s no animal reservoir from which the disease could bounce back into the population after it’s gone.”1


From the World Health Organization

The World Health Organization’s Pan African Tsetse and Trypanosomiasis Eradication Campaign seeks to eradicate the infectious disease and its fly vector throughout the African continent.

Most of these eradication efforts, both with malaria and trypanosomiasis, focus primarily on targeting the insect vectors, organisms which transport the parasitic organisms responsible for these diseases. Moreover, the task of targeting these vectors could be expedited with the recent advent of CRISPR-Cas9. Gene-editing technology provides a nuclear arsenal in terms of combating nuisance organisms. Researchers have devised mechanisms which modify key gene drivers in female mosquitoes that cause them to produce infertile offspring. Results show up to a 99.6% success rate.2 Biotech firm Oxitec has similarly tinkered with mosquito genes and between 2009 and 2010 released three million modified mosquitoes onto sites in the Cayman Islands. The firm reports a 96% reduction in mosquito populations within the first year of the trial. Trials conducted in Brazil ahead of the 2016 Olympic Games yielded similar success with reductions of up to 92%. With the reigns of evolution now in human hands, the possibility of disease eradication is within reasonable sight. The fanciful fairy tales of yesteryear are now front-page headlines.

Organisms often induce the extinction of other species. One could call it a law of biotic interaction. In fact, the competitive exclusion principle, or Gause’s law, states that when species compete for a limiting resource, the stronger competitor drives the weaker competitor to extinction. Even if the two organisms aren’t directly competing against each other, the actions of one can cause detrimental consequences for the other indirectly. But the conscious and intelligent eradication of an entire species is a trait unique to the human animal.

These concerted efforts of eradication differ even from our own illustrious history of inadvertent extinction events. While one could argue that extinctions caused by pollution, overexploitation, and habitat loss are too the result of intentional decision-making, many, including those most vocal on continuing these activities, would lament species loss as an unfortunate trade-off for modernity rather than a goal in and of itself.

But now, humanity stands on the precipice of power—a power never wielded before by a single species. The power to wipe out any organism that inconveniences us.

With this comes the obvious but important question—should we?

It is a subject not to be tackled likely. A subject that delves deep into questions of bioethics and conservation philosophy. A subject which, to my surprise, is relevant to the Pokémon World.

The Sludge Pokémon, Muk, as its name would suggest, is the literal embodiment of pollution. But Muk is much more than a Captain Planet-esque monster meant to teach the toll of pollution in the modern age, Muk is a downright public health hazard:

Its body is made of a powerful poison. Touching it accidentally will cause a fever that requires bed rest. (Pokémon Silver Version)

From Muk’s body seeps a foul fluid that gives off a nose-bendingly horrible stench. Just one drop of this Pokémon’s body fluid can turn a pool stagnant and rancid. (Pokémon Ruby Version)

Moreover, Muk not only poses a threat to human societies, but to the rest of nature as well:

As it moves, a very strong poison leaks from it, making the ground there barren for three years. (Pokémon Crystal Version)

A toxic fluid seeps from its body. The fluid instantly kills plants and trees on contact. (Pokémon, Diamond, Pearl, and Platinum Versions)

Its pre-evolution, Grimer, is no better. It’s Pokémon Silver entry states, “Wherever Grimer has passed, so many germs are left behind that no plants will ever grow again.” The mere movement of these creatures can wreak havoc on ecosystems, and a simple slip up around one of these guys can render a trainer bedridden—if not dead.


Now, if we ignore for a second the existential threats posed by the myriad of Pokémon in general, from a public health perspective, Muk and Grimer are serious health hazards, perhaps on par with malaria-vectoring mosquitoes in our world. This would perhaps make them prime candidates for eradication.

Given the advanced technology of the Pokémon world, PokéradicationTM should be a feasible task. The Pokédex even suggests a means by which this eradication could be carried out. Entries such as those in Pokémon Ultra Sun indicate that Grimer cannot exist in sterile environments, or else its internal load of germs which gives the sludge life dies. These Pokémon depend on sludge and industrial discharge from factories to replenish their depleted bacterial stores. Eradication could be as simple as denying Muk and Grimer a habitat by cutting off its pollution food sources and decontaminating infested areas where they proliferate. This would be similar to strategies used to combat malaria-vectoring mosquitoes such as limiting pools of stagnant water and decontaminating known mosquito breeding grounds.


WWII poster advising soldiers to prevent the proliferation of mosquitoes. From Wikipedia.

In fact, the task is so simple that it appears to have already been implemented, and to great success if the Pokédex is any indicator:

Their food sources have decreased, and their numbers have declined sharply. Sludge ponds are being built to prevent their extinction. (Pokémon Ultra Sun)

Because they scatter germs everywhere, they’ve long been targeted for extermination, leading to a steep decline in their population. (Pokémon Ultra Moon)

After recent environmental improvements, this Pokémon is now hardly seen at all. People speculate that it may go extinct at some point. (Pokémon Moon)

According to Pokémon Sun, Grimer, deprived of their industrial waste food source, have been on the decline in recent years. Pokémon Ultra Moon even goes as far to say that wastewater from factories is so clean these days that Grimer are “on the verge of extinction.”

Eradication efforts have been so successful that conservationists have constructed “sludge ponds” to prevent their extinction.

But should they? Should Muk and Grimer be left to go the way of Smallpox and Guinea worm?

A similar debate is being had in our own world regarding whether we should eradicate malaria-vectoring mosquitoes. More than 2 billion people face risk from malaria.3 WHO estimates there were 214 million cases of malaria in 2015, resulting in 438,000 deaths. Mosquitoes vector additional diseases too, such as West Nile Virus, Dengue Fever, and most recently Zika Virus, but malaria is by and far the mosquito’s most deadly passenger.


From The Guardian

Many health officials, policymakers, and even biologists endorse eradication. Others are more reluctant, citing both ethical and ecological concerns.

With smallpox the matter was simple in terms of ethical debate. The variola virus found few championing its right to life—researchers still dispute whether a virus even constitutes a living organism. Guinea worm, being so debilitatingly cruel in its parasitism and sadistically specialized to its human host drew few defenders too. But mosquitoes continue an entire family of their own, Culicidae, comprised of over 3500 species—only 100 of which require human blood to develop their eggs. Even fewer vector the mosquito’s most deadly passenger. Malaria is only transmitted by females of the genus Anopheles, resulting in only about 40 or so species that actually pose significant threat to public health. Yet for some, even those forty are forty too many.

The debate over eradication of any organism ultimately boils down to a discussion of values. There are three types of value a species can possess—ecological value, instrumental value, and intrinsic value.4

These three values also reflect three key aspects when considering eradication. So, let us explore the possibility of eradication—both of mosquitoes and Muk/Grimer—from these three perspectives.

Ecological Value

Ecological value is value derived from the contribution a species makes to the integrity, health, stability, or good functioning of its ecosystem. In ecology, an analogous term would be ecological function, or the processes which an organism provides for an ecosystem. Such processes can include the cycling of nutrients, breakdown of dead organic matter, or detritus, distributing resources, among many others. These functions help form an organism’s ecological niche. A niche can be thought of as an organism’s job description—where it lives, what it does, and how it does it. Like jobs, there are only so many niches to go around depending on your particular habitat. So, when a niche becomes available, either through de novo creation or a vacancy, organisms will fill it. Or so, is argued by supporters of eradication.

Janet Fang writes in Nature that the “ecological wound” dealt by the eradication of mosquitoes would heal quickly as other organisms would fill its niche.5 Currently, mosquitoes main functions are as prey and pollinators.


The mosquito fish. Commonly used as biocontrol for mosquitoes, but could face extinction if its prey are eradicated. From

Consequently, the eradication of mosquitoes could lead to the extinction of highly specialized mosquito predators, such as the mosquitofish. The potential cascading trophic effects may prove detrimental. Alternatively, other organisms could very well fill those emptied niches as well.

However, in tundra ecosystems the loss of mosquitoes would be felt a little harder. In the Arctic tundra, biblical swarms of mosquitoes emerge during snow melts, blanketing the landscape in black clouds thick enough to choke out caribou. It is thought that migratory birds would suffer a 50% drop in population if these vast food sources were removed.5 However, evidence from bird stomach samples suggests a different scenario in which migratory birds acquire nutrients from an alternative insect, most likely midges which are a more important food source for migratory birds.

Similarly, the pollination conducted by mosquitoes could leave thousands of plants without pollinators, but researchers predict that other organisms would fill this niche too in the event of mosquito eradication.

But adult mosquitos are not the only ones to take into consideration. Mosquito larvae, suspended in water, contribute to detritus processing in aquatic systems. However, this function too can be carried out by other organisms. “Lots of organisms process detritus,” says Steven Juliano, a medical entomologist at Illinois State University in Normal. He tells Nature, “Mosquitoes aren’t the only ones involved or the most important. If you pop one rivet out of an airplane’s wing it’s unlikely that the plane will cease to fly.”


Streams facilitate many ecological functions, including detritus decomposition. From Campanario Biological Station, Costa Rica. Taken by author.

But, popping out rivets on a plane is not a good idea if you’re not entirely sure of how the plane works or what each rivet does. You could be popping a vital rivet, or a rivet supporting a vital rivet.

And quite simply, we do not fully understand how Spaceship Earth works, nor do we understand fully the function of this mosquito rivet.

For example, let us return to our Arctic mosquito clouds. Caribou alter their migration paths to avoid these swarms. This may seem inconsequential, just as popping the single rivet seems trivial. But, if you were to remove the mosquito swarms, then you would also shift caribou migration. Altering caribou migration may lead to altering the landscape as traditional grazing locations change. “A small change in path can have major consequences in an Arctic Valley through which thousands of caribou migrate,” Fang writes, “trampling the ground, eating lichens, transporting nutrients, feeding wolves, and generally altering the ecology.”

You start off by popping one rivet but through that singular action loosen the whole set.

Muk and Grimer, a mostly urban Pokémon, does not interact much with biota beyond its own infestation of germs. And what interaction it does have appears to be detrimental if anything.

Although, Muk and Grimer do feed on Trubbish…

Unsanitary places are what they like best. They can be spotted in Alola, often with Grimer in hot pursuit. (Pokémon Sun)

Poisonous gas leaks out of it when  it breathes. Muk that catch a whiff of that stench will come drooling. (Pokémon Ultra Sun)

…but both are literally garbage so any effect is negligible.

While mosquitoes at least contribute to their ecosystems in some capacity, Muk and Grimer offer little, if any, ecological value. But instrumental value is a different story.

Instrumental Value

Instrumental value is derived from a species usefulness to humans. This can come in the form of natural resource value, recreational value, medical value, or even economic value. Again, ecology provides an analogous term, ecological services, or functions that benefit human societies. Pollination is a prime example of an ecological service, as many agricultural crops rely on natural pollinators.

As previously discussed, mosquitoes are pollinators for thousands of plants. However, this function fails to be a service for the simple reason that none of those plants are of any use—commercial or otherwise—to humans. In this respect, mosquitoes provide no ecological services to humans aside from driving you back inside on a warm summer day. Although, some have argued that this may very well be a service in disguise.

Mosquitoes have been a deterrent for more than lakegoers. “Mosquitoes make tropical forests, for humans, virtually uninhabitable,” argues science writer David Quammen. Indeed, the tropical infestation of mosquitoes has been a limiting force in human expansion in many cases. Early attempts at constructing the Panama Canal came to a halt as casualties from malaria-vectoring mosquitoes took its toll on the workforce. Human expansion has been limited by mosquito “walls”, preserving tropical habitats for a time. But then we invented bug spray. The Panama Canal was completed after efforts to limit mosquito proliferation were taken—limiting mosquito breeding grounds and poisoning infested water. The mosquito wall might have held against primitive man, its defenses have not proven to hold up over time.

While mosquitoes lack ecological services, Muk and Grimer in this most recent generation of Pokémon games have proven themselves useful in one key capacity, and that might very well be their saving grace.

Unlike the mosquito, which seems only particularly good at sucking blood and vectoring disease, Muk and Grimer have a knack for processing industrial waste. Born from sludge, these Pokémon sustain themselves off pollution and garbage. In fact, they need to feed on sludge to maintain the loads of germs that give them life. This can, and has been, exploited for human benefit—at least in Alola:

Grimer, which had been brought in to solve a problem with garbage, developed over time into this form. (Pokémon Sun)

There are a hundred or so of them living in Alola’s waste-disposal site. They’re all hard workers who eat a lot of trash. (Pokémon Ultra Sun)

In fact, the use of Grimer and Muk to break down and consume environmental pollutants has a name in our world, bioremediation, and is currently in use to clean up contaminated sites around the world.


Grimer and Muk acquired their current Alolan forms as a result of their bioremediation services in Alolan waste treatment facilities.

The bioremediation services provided by the Sludge Pokémon might save them, and the lack thereof in mosquitoes might damn them. But do these creatures need to provide any service to humans to be worthy of life? Does value stem from the species in and of itself?

Intrinsic Value

Many argue that there is an inherent sanctity of life. Some would even take this a step further and declare a biological egalitarianism of sorts, that no life is more valuable than any other lifeform, humans included. Those that hold this biocentric philosophy would argue species possess an intrinsic value all in and of themselves, independent of their use or value to man. It is a worldview in contrast to the anthropocentrism prevalent in much of the West, where humans concerns take priority over nature, and all that is done is considered with human wellbeing in mind.

Writing for the Journal of Medical Ethics, Jonathan Pugh deconstructs the faults in what he calls the “Singerian View” named after notable musician and animal rights activist Peter Singer. Pugh argues that people who hold to the Singerian View, that all life is sacred, cannot practically apply this position to their everyday life. Most people care little of killing vegetables or condemning millions of microbes to an alcoholic holocaust every time they apply hand sanitizer.

A more plausible view on this matter is to claim that the moral permissibility of killing a living thing depends on whether it has moral status. For a creature to have moral status means that the creature deserves certain forms of moral protection, and a creature’s moral status is often said to depend on the kinds of capacities it has.6 (Pugh 2016)

If one were to truly view all life as sacred than the eradication of smallpox is less a triumph of modern medicine and more a horrific act of “speciecide.”

Should the eradication of mosquito or Muk be seen as any more horrific than that of smallpox?

I hold a biocentric worldview—to an extent. I believe in an intrinsic value to life, that such life can be derived simply from the scarcity of biological life in the Universe as far as we know it. Rarity in and of itself constitutes value. Even if life beyond this sphere were discovered, even if it were discovered somewhere as close as Mars, it still would not diminish the worth of Earth life, as the Tree of Life from which all species stem is a uniqueness to the Universe. Yet, I agree with Pugh in that a practical application of biocentrism or the Singerian View is impossible. Even if a radical biocentrist were to kill themselves to spare other organisms their oppression, the burial or cremation of that individual would have countless ecological impacts, however miniscule they may be. Man can never fully sever umbilical cord to Mother Nature whom gave it life. This, I believe, is the fatal flaw of many well-intentioned activists. In a cruel irony, in trying to enact biocentrist policy they adapt a bastardized form of anthropocentrism, portraying man as the antagonist of all that is natural and constructing an artificial binary of that which is of man and that which is of nature.

I believe all organisms have something to offer. What humans have to offer is something no other organism possesses—an intelligent mind with which we can explore, examine, and understand the natural world. A power to wield this knowledge and determine the fate of species.

Every decision is a trade-off. That is the cost of having this awesome power, we are left with the decision-making. We may choose to eradicate any species that causes harm to our own. We may choose to suffer through until a better solution becomes available. But the fact that we have a capacity to make that choice and execute it to our will is a sobering, yet remarkable responsibility.

Accurate Pokédex Entry: Targeted for eradication for being a public health hazard in recent decades, Muk have been driven to near extinction. The last remaining populations reside either in protected sludge pools or waste treatment facilities where they are used for bioremediation. The ecological services provided by the Sludge Pokémon may stave off its previously imminent extinction.

Click the Go Pokémon! button to subscribe and stay up to date on all the latest news in Pokémon Biology, and be sure to follow us on Twitter @PokeBiology.

Works Cited

  1. Roberts, Leslie and Martin Enserink. 2007. Did They Really Say…Eradication? Science 318:1544-1545.
  2. Hammond, A. et al. 2016. A CRISPR-Cas9 gene drive system targeting female reproduction in the malaria mosquito vector Anopheles gambiae. Nature Biotechnology 34:78-83.
  3. Greenwood, B. M. et al. 2008. Malaria: progress, perils, and prospects for eradication. The Journal of Clinical Investigation 118:1266-1276.
  4. Sandler, Ronald. 2009. The Value of Species and the Ethical Foundations of Assisted Colonization. Conservation Biology 24:424-431.
  5. Fang, Janet. 2010. A World Without Mosquitoes. Nature 466:432-434.
  6. Pugh, Jonathan. 2016. Driven to extinction? The ethics of eradicating mosquitoes with gene-drive technologies. Journal of Medical Ethics 42:578-581.

Is Magikarp an Invasive Species?

I Love Magikarp

Totally pathetic, unreliable.

These are the first words used to describe the lowly Fish Pokémon in The Magikarp Song. And while the song is ultimately an ironic ode to the oft-mocked Pokémon peppered with tongue-in-cheek jabs at the fish, one only need take a cursory glance at Magikarp’s Pokédex history to gain a sense that the scientific community—or whoever authors these fantastical entries—does not particularly hold Magikarp in the highest esteem:

In the distant past, it was somewhat stronger than the horribly weak descendants that exist today. (Pokémon Red and Blue Versions)

An underpowered, pathetic Pokémon. It may jump high on rare occasions, but never more than seven feet. (Pokémon Gold Version)

This weak and pathetic Pokémon gets easily pushed along rivers when there are strong currents. (Pokémon Crystal Version)

Magikarp is a pathetic excuse for a Pokémon that is only capable of flopping and splashing. This behavior prompted scientists to undertake research into it. (Pokémon Ruby Version)

It is virtually worthless in terms of both power and speed. It is the most weak and pathetic Pokémon in the world. (Pokémon FireRed Version)

It is said to be the world’s weakest Pokémon. No one knows why it has managed to survive. (Pokémon Diamond Version)

Many of the lighthearted lyrics of The Magikarp Song are lifted directly from the Pokédex, but only when read alone without the catchy tune playing in the background can one truly taste the venom seeping from the belittling and, honestly, slanderous text.

The main ethos of this blog is that just as there is something to be learned from every organism, so too there is also something to be learned from every Pokémon. And The Pokémon Games seem to have a similar message at their core—that all Pokémon, big or small, strong or weak, have something to offer. The immortalized words of Elite Four Karen speak to this truth:

Strong Pokémon. Weak Pokémon. That is only the selfish perception of people. Truly skilled trainers should try to win with their favorites. (Pokémon Silver, 2000)

Yet, the mockery of Magikarp throughout the Pokédex seems to contradict this central core message.

It was my original intent for this Pokémon Day, to write in defense of Magikarp. To extol its high fecundity and amazing osmoregulation, to applaud its persistence throughout the ages despite being “weak” and to explore the life history traits of Magikarp and the evolutionary trade-off that might have led to its current “weak” form—topics that I may cover in the future.

But, during my research, I came across several troubling traits in Magikarp that lead to a worrisome conclusion that might explain why the Pokédex displays such distain for the Fish Pokémon. Magikarp is an invasive species.

We’ve discussed invasive species previously regarding the Alolan forms of Rattata and Meowth (Alolan Rattata and The Feral Cat Problem), and it is now consensus opinion within the community that invasion is a key theme of the Generation VII games. Additionally, it could be argued that most, if not all Pokémon are invasive, or nonindigenous at the very least. However, I propose that Magikarp is not only invasive, but is having detrimental impacts on ecosystems all across the Pokémon World.


Is an Invasive by Any Other Name Just as Sweet?

You may have noticed I’ve been careful not to use invasive and nonindigenous interchangeably. Anyone whose been introduced to the topic before may be accustomed to one or both or any of the tens of terms used to describe nonindigenous species—alien, introduced, exotic, imported, naturalized, transient—the list continues for as long as there are papers written on the subject. This abundance of terms can lead and has led to much confusion about what exactly is being described. Is the discussion limited to only harmful organisms? Are benign organisms invasive? What counts as alien? Are humans the only vector by which these organisms can be introduced?

Even the most frequently used term “invasive” has found itself carrying differing definitions throughout the scientific literature where it has been used as:

  • A synonym for nonindigenous
  • An adjective for nonindigenous species that have invaded natural areas
  • A term used to distinguish between nonindigenous species established in cultivated habitats (i.e. domesticated farm animals) and those established in natural ones (i.e. “the wild”)
  • A term used to describe widespread nonindigenous species
  • A term used to describe widespread and harmful nonindigenous species

If multiple, differing definitions can be derived from a single term, the compounding effect of having tens of terms in use can lead to even more confusion for scientists and especially the public. Additionally, even if we limit ourselves to “invasive” problems can arise when discussing nonindigenous species as generalizations could easily lump together organisms that do not have comparable effects on their habitat.

Here’s an example. The common goldfish is considered invasive under two of the above definition as it is (1) nonindigenous to the United States, and (2) widespread through its invaded habitat since its introduced into American waterways thanks to neglectful fish owners. However, goldfish rarely achieve high enough densities to cause significant harm to their habitats. Contrast this with the zebra mussel, a textbook invasive species from Eurasia which has cleared waterways and clogged pipes throughout North America. The zebra mussel is both widespread and found at high enough densities to have adverse effects on its habitat. Both organisms are considered invasive, yet in a generalized discussion of invasive species they do not appear to be exhibiting the same phenomenon.


Naturalized goldfish (left). Zebra mussel infestation (right).

Furthermore, use of invasive terminology can lead to misleading conclusions about the organisms themselves. As Colautti and MacIsaac (2014), authors of the paper from which this article draws heavily from, point out, the use of this language reinforces the mistaken idea that invasive species are some type of taxonomic group, that their invasive qualities are intrinsic to their being, forgetting that all nonnative species are native somewhere.

“Indeed the very terms used to describe NIS are misnomers in that nonindigenous species are actually nonindigenous populations of species. In other words, the same ‘species’ that are nonindigenous, naturalized, or invasive in one area are native somewhere else.” (Colautti and MacIsaac 2014)

Thus, Colautti and MacIsaac devised a framework to better classify nonindigenous species using a more neutral terminology. This the framework from which I will work within for the duration of this article.

Colautti and MacIsaac conceptualize nonindigenous species, referred to as “propagules” (a piece of a plant that can be snipped and planted elsewhere to form a new plant), as advancing through five stages.

First is Stage 0—the potential propagules still reside in their native “donor” habitat. The propagules enter Stage I when they are first “snipped” from their native habitat and transported elsewhere. If the propagules survive transport and release into their new environment they enter Stage II. Once introduced, propagules may achieve Stage III where they are “numerically rare” but have the potential to further establish themselves. From here, propagules can enter two diverge paths into Stage IV—become widespread (Stage IVa) or become dominant (Stage IVb). Once an organism has become both widespread and dominant, they have entered Stage V—what most people and conservation organizations would consider “invasive”.


From Colautti and MacIsaac (2014)

This new framework allows for distinction between nonindigenous species of varying ecological influence. Let’s return to our previous example. Under this framework, the goldfish would be classified as Stage IVa (widespread), while the zebra mussel would be Stage V (widespread and dominant).

So where does Magikarp fit into this framework?


Magikarp—the Invasive Pokémon

There are currently no hard-and-solid predictors of whether any given species will become invasive if introduced into a novel environment, but there are a few general traits that most successful invaders tend to have. Firstly, successful invaders typically mature early and reproduce rapidly. In essence, they adopt the reproductive strategy of freaking a lot, freaking early (censored for your children’s viewing). Additionally, good invasive species have high dispersal rates—are good at getting their offspring out into the further reaches of their habitat to become widespread and check off one box towards becoming a Stage V species.

Another good trait to have is being able to adapt to a wide range of environmental conditions. They are often tolerant of adverse conditions that other organisms would typically not thrive in, such as anoxic (low oxygen) or heavily polluted habitats. This adaptability can be achieved sometimes through phenotypic plasticity, when outward expression of certain traits changes depending on the environment (we talked more about this in Eeveelution Epigenetics). Successful invaders are also usually generalist, being able to consume a wide range of food sources and adapt to whatever happens to be lying around in their environment.

Lastly, most invasive species have an association with one species in particular—homo sapiens.

Humans introduce a lot of nonindigenous species to foreign environments. A review of nonindigenous species in the United States estimates 50,000 nonindigenous species in the US costing $137 billion annually in damages and loss of recreational value (Pimentel et al. 2000). Most are benign and are intentionally brought over, such as domesticated farm animals like dairy cows and chickens. Many are imported as pets, like the Burmese python which now infamously ravages the Florida Everglades. Others hitch a ride unintentionally, such as the zebra mussel which stowed away in the ballasts of cargo ships. As a rule of thumb, only 10% of introduced organisms will become invasive—only 4,500 of the 50,000-nonindigenous species in the US are considered invasive. This may explain why in regions abundant with nonindigenous Pokémon, only a few become invasive like Magikarp.

And Magikarp does appear to possess quite a few invasive qualities.

For starters, Magikarp seems to have fully adopted the freak-a-lot-freaking-early lifestyle. In game, Magikarp and Gyarados require the fewest egg cycles to hatch—indicative of a fast and early maturity. Additionally, the Pokédex entry for Pokémon Sun suggests Magikarp is also a rapid reproducer:

Although weak and helpless, this Pokémon is incredibly fertile. They exist in such  multitudes, you’ll soon grow tired of seeing them. (Pokémon Sun)

Pokémon Ultra Moon states that Magikarp can be found in “waters all over the world!” and this mostly rings true as Magikarp is present in every regional Pokédex except for Unova—possibly due to stricter regulations on introducing nonindigenous species since it is a US-based region. All of this would suggest high dispersal capabilities in reproducing Magikarp.

Furthermore, Magikarp displays a high tolerance across a wide range of environmental conditions. From the cold lakes of Sinnoh, to the polluted waters of Celadon City in Kanto, and the sunny shores of Alola, Magikarp thrives. Its entry from Ultra Moon speaks to this:

Thanks to their strong hold on life, dirty water doesn’t bother them at all. They live in waters all over the world! (Pokémon Ultra Moon)

Magikarp even exhibits some form of phenotypic plasticity in its ability to switch from fresh to saltwater, as Pokémon Yellow states, “It can be found swimming in seas, lakes, rivers, and shallow puddles.”

Most importantly, Magikarp has a close association with humans in the Pokémon World. In Kanto, and even strictly regulated Unova, Magikarp are sold as pets, similar to goldfish, a species of Asian carp which serves as the inspiration for Magikarp. In fact, this is a likely scenario for its introduction through the waters of the world. Tourists bought these Pokémon as pets while on vacation in Kanto and release them upon their return to their native region, as is the case with many exotic pets. Another possibility is that Magikarp was exported from its assumed native habitat of Kanto for the purposes of aquaculture else, just as several species of Asian carp were introduced into the US and Europe as foodfishes.

So where does this leave Magikarp under the framework established earlier by Colautti and MacIsaac? Well, by the evidence presented thus far, Magikarp is at least in Stage IV. Specifically, we know Magikarp is widespread (IVa). But is it dominant?

Dominance, in ecology, refers to how much biomass an organism constitutes in comparison to its competitors. In simplest terms, dominance depends on who is most numerous.

We obviously lack population data on Pokémon, so we’ll have to make do with what information we do possess—where each Pokémon can be found. I’ve taken all the fish Pokémon of each region where Magikarp can be found and compared the percent of the total region’s locations (routes, cities/towns, landmarks) that each Pokémon could be found in. And the results are not hopeful.

In Kanto, the presumed home range of Magikarp, there are only five “fish” Pokémon—Magikarp, Goldeen, Seaking, Horsea, and Seadra (yes, seahorses are fish). Of these five, two display dominance—Goldeen who can be found in 45% of locations, and Magikarp who covers 50% of Kanto. This shared dominance is to be expected in its native habitat, and further supports Kanto as being its native region


But in foreign regions, Magikarp truly makes a Splash.

In Hoenn, Magikarp competes with thirteen other fishes yet is present in 43% of locations. The closest competitor is Sharpedo at 15%, almost three times less than that of Magikarp. This trend holds for Sinnoh too, with Magikarp in 46% of locations. Native fishes like Finneon and Lumineon only have 10% coverage each. Kalos is a bit of an outlier, as it’s the only region with a pretty even distribution of fishes. There is no dominant fish and the fish with the greatest coverage is Luvdisc at 10%, greater than Magikarp in this region. This may be due in part to the massive richness found in Kalos—home to 24 different fish Pokémon, the most of any region. The greater competitions could perhaps damper the effects of Magikarp encroachment onto foreign territory.


However, in Alola, Magikarp is dominant once again with 30% coverage across these tony islands, outcompeting even Wishiwashi (17%). Furthermore, when compared with another widespread nonindigenous species who happens to be found all the same regions—Goldeen—Magikarp was found to have significantly greater coverage still.


So it does appear that Magikarp is at Stage V in at least three separate regions of the Pokémon World. But what impacts could Magikarp have on its invaded habitats.


Malicious Magikarp

Nonindigenous fishes in the US cost an estimated $1 billion annually in damages and losses. Introduced carp in particular have become a notable nuisance in American waterways. Asian carp have been known to leap up to 10 feet from the water when water motorists disturb their schools. In 2015, one man had his nose fractured and brow bones shattered by a leaping carp while inner tubbing on the Mississippi River.

An underpowered and pathetic Pokémon indeed.

Moreover, invasive carps can have devastating impacts on ecosystems. Asian carp decrease the amount of suspended vegetation in waterways and often deplete communities of benthic macroinvertebrates (Matsuzaki et al. 2009), organisms vital in the leaf breakdown process and export of organic materials and nutrients to downstream systems. Additionally, carp increases ammonium concentrations which can lead to algal blooms and subsequent anoxic conditions. Even in small numbers carp can be responsible for the deterioration of entire ecosystems. Bayer et al. (2009) found that when even carp biomass was 3-4 times lower than what is typically found in invaded systems, these fishes can reduce vegetation cover by 50%, halving waterfowl abundance in the process—all within the span of 7 years.

Further increases in carp left only 17% of the original surface vegetation and reduced waterfowl abundances to a slim 10% of original numbers.

If Magikarp is wreaking havoc anywhere near the scale of real-life carp, then the animus which Pokédex authors feel toward the Fish Pokémon is understandable—but ultimately misguided.

It is important in these discussions about invasive species to remember not to conflate the invasion of the species and the damage it does with the species itself. There are no “bad” animals just like there are no “bad” Pokémon, only bad humans who allow them to do bad things.

There is nothing intrinsically wrong with these organisms, they are just really good at doing what they do. Zebra mussels are really good at filtering water. Carp are really good at consuming vegetation. These traits would otherwise serve them well in the appropriate environment, and they serve really well in novel ones. It just happens that in these novel environments, their superb niche fulfillment happens to be detrimental to all other biota within the vicinity.

We must separate the damage from the organism and take a look in the mirror because you could say we are the most destructive invasive species—having conquered every continent and left our footprint on almost every habitat.

83% of terrestrial land is affected by human activity, and we’ve put to use 98% of Earth’s farmable land (Sanderson et al. 2002). Where oceans and mountains blocked the spread of potential invaders, humans provided a ferry, a bridge to novel worlds and novel niches. We were their vector into worlds unknown. And we are still reaping what we have sown.

So spare Magikarp your hate.

Because you’re totally pathetic, unreliable.

Happy Pokémon Day.


Accurate Pokédex Entry: A popular Kanto pet, Magikarp has since been introduced to waters all over the world! However, its rapid reproduction and high tolerance for polluted waters has allowed it to spread into almost every aquatic habitat and has become the dominant fish Pokémon in many regions, outcompeting even native species.

Click the Go Pokémon! button to subscribe and stay up to date on all the latest news in Pokémon Biology, and be sure to follow us on Twitter @PokeBiology and while you’re at it follow the author @JaredIsAWriter.


Works Cited

Bajer, P., G. Sullivan, and P. Sorensen. 2009. Effects of a rapidly increasing population of common carp on vegetative cover and waterfowl in a recently restored Midwestern shallow lake. Hydrobiologia 632:235-245.

Colautti, R. I. and H. J. MacIsaac. 2014. A neutral terminology to define ‘invasive’ species. Diversity and Distributions 10:135-141.

Matsuzaki, S., N. Usio, N. Takamura, and I. Washitani. 2009. Contrasting impacts of invasive engineers on freshwater ecosystems: an experiment and meta-analysis. Oecologia 158:673-686.

Pimentel, D., L. Lach, R. Zuniga, and D. Morrison. 2000. Environmental and Economic Costs of Nonindigenous Species in the United States. BioScience 50:53-65.

Schankman, Paul. 31 Aug 2015. Pleasant Hill man injured by flying Asian carp. Fox 2 now St. Louis. Accessed 20 Feb 2018.



Kingler-Cloyster Coevolution?

Coevolution main banner

Some teachers make the mistake of teaching evolution as a singular process which involves only a single isolated population of organisms that stumble upon complexity through a mix of mutation and genetic drift. But evolution is a dynamic multifaceted process involving a whole host of organisms cooperating, competing, and capturing each other. In many cases, these interactions spawn a cyclical feedback loop wherein a trait in Species A drives changes for a trait in Species B, which leads to further change in Species A, and then again in Species B, and so on and so on, back and forth these two evolutionary players go in a game that can only end in escape or extinction.

This wheel of reciprocal selection is what we call coevolution, and drives many of the interactions we observe in the natural world from the antagonistic relationship between predator and prey, to more mutualistic ones between equally contributing and benefiting partners, as is the case with clownfish and sea anemone. Coevolution can produce many extreme phenotypes. Darwin, for example, whilst forming his grand theory of evolution, was sent a rather unusual orchid which would eventually bear his name. This orchid possessed a very long nectar spur. From this, Darwin predicted that there must be some organism out there with a tongue of matching length. Indeed, there was, named Morgan’s sphinx moth, whose lengthy proboscis can indeed reach the nectar at the bottom of the spur. Coevolution in action.

Darwins orchid and moth

Indeed, much of the diversity observed in nature is a product of coevolution, and while skimming the Pokédex it became apparent to me that such a process might in fact be driving at least some of the extreme phenotypes found in the Pokémon World. Even given relatively little information on each individual Pokémon, there is enough to make a considerable argument for coevolution occurring in Pokémon.

Perhaps the most likely candidates for Pokémon Coevolution are Kingler and Cloyster.

Classified as the Pincer Pokémon, Kingler draws design inspiration from fiddler crabs whose males possess a single oversized claw, a product of sexual selection. While fiddler crabs mainly use their oversized claw to literally wave down mates—as it proves useless for feeding purposes ironically enough—Kingler reportedly use their claw in their predator efforts against their bivalve prey, Shellder and Cloyster:

Said to be capable of prying open Shellder and Cloyster shells using its 10,000-horsepower pincer. (Pokémon Stadium)

But more interesting yet is the sheer amount of power that lone claw possesses—10,000 horsepower! In fact, the Pokédex makes repeated mention of this number:

The large pincer has 10000 hp of crushing power. However, its huge size makes it unwieldy to use. (Pokémon Red Version and Blue Version)

One claw grew massively and as hard as steel. It has 10,000-HP strength. However, it is too heavy. (Pokémon Yellow Version)

Coined by the inventor James Watt (yes, that watt), horsepower (hp) describes the power a horse exerts in pulling1. Specifically, Watt found that a horse could exert enough force to pull at about 33,000 foot-pounds per minute, or alternatively, 746 watts. This can also be expressed in joules (1,055 joules) as well as Calories (0.252 Calories)2. Most market cars do not exceed 500 horsepower. On the low end, a Ford escort has 110 hp. While on the high end, a Ferrari 355 F1 caps off at about 375 hp. So in terms of engine power, 10,000 hp is ridiculous. For a visual, here is the difference between an 850 hp engine and a 10,000 hp engine.

However, Kingler does not possess an engine but a pincer, which in essence is a simple machine, a lever. Kingler even operates it as such, prying open Shellder’s shell with an egregious amount of force. To measure the mechanical horsepower of Kingler’s pincers, we need only apply the original definition of horsepower—33,000 ft-lb per min—to the Pincer Pokémon.

With some quick arithmetic, we find that Kingler’s prying pincer motion can move 330,000,000 ft-lb per min, or alternatively, 7,456,999 watts. For a better visualization, a lightbulb typically requires 60 watts of power to run for one hour. The Eiffel Tower uses about 20,000 lightbulbs3. If the energy from Kingler’s pincer were converted into electrical energy, it would be able to power every light on the Eiffel Tower for 275 hours, or about eleven and a half consecutive days. And that’s only one crab. A complete team of six Kingler could power the Eiffel Tower for 1,650 hours or 69 days.


Considering the sheer power this crustacean wields, one can only wonder—what would cause Kingler to evolve an unnecessarily powerful pincer in the first place?

Enter Cloyster, the Bivalve Pokémon, who aside from being an admittedly lazy portmanteau of clam and oyster, is a well-recognized defensive tank in competitive Pokémon circles. With a base defense of 180, Cloyster has the highest base physical defense of any Water-Type Pokémon (not counting Mega Evolutions, otherwise is a tie with Mega Slowbro). Furthermore, the Pokédex makes constant reference to the durability of its shell defenses, describing its shell as “harder-than-diamonds” and “impossible to shut” when closed, as well as being capable of withstanding hits from bombs and even missiles:

For protection, it uses its harder-than-diamonds shell. It also shoots spikes from the shell. (Pokémon Yellow Version)

Its shell is so hard, it can even withstand a bomb. No one has ever seen what is inside its shell. (Pokémon Stadium)

Once it slams its shell shut, it is impossible to open, even by those with superior strength. (Gold)

Even a missile can’t break the spikes it uses to stab opponents. They’re even harder than its shell. (Pokémon Crystal Version)

Its shell is extremely hard. It cannot be shattered, even with a bomb. The shell opens only when it is attacking. (Pokémon FireRed)

Its hard shell cannot be shattered—not even by a bomb. The contents of the shell remain unknown. (Pokémon Sun)

All things considered, Cloyster is an incredibly durable bivalve…almost too durable for what it needs to endure. Sure, clams get battered by rough tides, and in the Pokémon World I’m sure being able to withstand forces comparable to a bomb blast has its advantages, but even in the context of the Pokémon World it seems rather excessive considering Pokémon in general seem to be rather durable creatures if even the tiniest Skitty is able to shake off a Hyper Beam to the face.

However, this all makes sense within the context of an evolutionary arms race, an actual term used to describe a form of coevolution in which the species involved each evolve countermeasures to the adaptation of the other4.

A close parallel to the possible Kingler-Cloyster system in our world can be found with Sinistrofulgur, a predatory whelk and its bivalve prey, Mercenaria. The whelk feeds on Mercenaria by mounting the bivalve chipping away at its prey’s shell. But what does a whelk use for chipping in leu or arms or pincers? Well, its own shell of course. Sinistrofulgur will butt the “lip” of its own shell against Mercenaria to chip away at its prey’s shell, in some cases even fracturing its own shell in the process. Thanks to the fossil record, many artifacts of these predatory encounters are preserved, and scientists can not only track the size and thickness of these shells over evolutionary time, but also observe which attempts by Sinistrofulgur on breaking open Mercenaria shells were successful by examining fossilized chips in ancestral Mercenaria.

Unsuccessful whelk attacks

Examples of unsuccessful whelk attacks preserved in fossilized Mercenaria. From Dietl (2003).

One study5 did exactly that, and found Mercenaria with larger, thicker shells survived more encounters, and thus, shell size and thickness increased over time. Likewise, researchers observed an in increase in shell size in Sinistrofulgur, likely a response to the increases in size and thickness of their prey.


Mercenaria (above) and predatory Sinistrofulgur (below). From

Indeed, a similar arms race could have occurred millions of years ago in the prehistoric waters of proto-Kanto. A Kingler-like Pokémon preys on a soft-shelled bivalve like modern Cloyster. However, individuals with harder shells survive the assaults of proto-Kingler and are favored by the invisible hand of natural selection. As a result, proto-Kingler who are unable to successfully access the protected flesh of their prey die out, but proto-Kingler who pack a little more punch in their pincers proliferate. Consequently, Cloyster evolves harder shells. Even stronger pincers are favored. This exchange continues for millions of years. Cloyster evolves harder shells to avoid predation, Kingler evolves stronger pincers to prey on Cloyster. A perpetual stalemate with no one side ever achieving lasting victory over the other. Finally, we reach the modern age and the arms race has resulted in a 10,000-horsepower crustacean and a diamond-shelled bivalve.


But what evidence is there of this arms race?

Pokémon, admittedly, has a rather sparse fossil record (although to be fair, their paleontologist can revive what few fossil taxa they find, so they have us beat in that respect). However, we are provided with some information that could be used as a starting point.

For starters, an obvious prerequisite for coevolution is occupying the same habitat. In all the main-series entries in the Pokémon franchise, Kingler and Cloyster themselves occupy only one location together, the waters off the coast of Route 13 in Pokémon Black Version and White Version. However, their pre-evolutions can be found together throughout a plethora of games and locations as listed in Table 1.

Table 1 Cloyster

Table 1. Shared locations of Kingler and Cloyster and their respective pre-evolutions.

Furthermore, the games provide us with a quantifiable measure of these traits in the form of base stats. If we compare the base stats of all the Pokémon found on Route 13—the only location where both Cloyster, Kingler, and their respective pre-evolutions are found together—we find in Figure 1 and Figure 2 that not only do Cloyster and Kingler have the highest base defense and attack respectively in this habitat, but their pre-evolutions are not far behind. Moreover, Kingler has comparable base defense and Cloyster comparable base attack, both of which are still greater than the majority of other Pokémon in the same area.


Figure 1. Base physical defense for Pokémon found on Route 13 (Black and White Versions) through surfing.


Figure 2. Base physical attack for Pokémon found on Route 13 (Black and White Versions) through surfing.

While confounding variables may exist, this preliminary evidence does suggest there is some relationship between these two Pokémon. However, the extent of that relationship remains to be determined, but in the meanwhile we can at least update the Accurate Pokédex.

Accurate Pokédex Entry (Cloyster): As a result of an evolutionary arms race, it has evolved a shell harder than diamond and can even withstand bomb blast. This durability is required if it wants to survive the crushing claw of its main predator, Kingler.

Accurate Pokédex Entry (Kingler): With a crushing power of 10,000 horsepower, its pincer could theoretically power the Eiffel Tower for eleven days. Such strength is necessary to open the shells of its bivalve prey, Cloyster.

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Works Cited

  1. “Horsepower.” Merriam-Webster, n.d. Web. 11 Feb. 2017.
  2. Marshall Brain “How Horsepower Works” 1 April 2000. 11 February 2017
  3. Lauter, Devorah. “Eiffel Tower Goes Green” 1 August 2000.
  4. Bergstrom, Carl T., and Lee Alan Dugatkin. Evolution. 2nd ed., W. W. Norton & Company, 2016.
  5. Dietl, Gregory P. 2003. Coevolution of a marine gastropod and its dangerous bivalve prey. Biological Journal of the Linnaean Society 80:409-436.