Kingler-Cloyster Coevolution?

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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.

1 thought on “Kingler-Cloyster Coevolution?

  1. Fraczewski

    You might be onto something with relationship of these two species. In the Generation I index list, which tells us roughly the order in which the Pokemon were designed, Kingler is #138 and Cloyster is #139. Their preevolutions had already been designed and put into the game’s code at this point though (Shellder being #023, Krabby #078).

    Liked by 1 person


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