Coming soon to Discovery Channel: Kaiju Week! Kaiju: Fact or Fiction? Kaiju: You Can’t Prove They Aren’t Real. (Image from Pacific Rim. Go see it, it’s awesome, there are robots punching monsters.)
Friends, you know I’m no fan of the ocean, primarily because there are jellyfish in there. Sure, the world’s oceans are full of strange, wild, beautiful creatures that frankly boggle the imagination, but the fact is that the majority of them wouldn’t mind feasting on your delicate human flesh. So generally I don’t like to think about what may be lurking in the depths of the sea, waiting to make a meal of us all. I try to ignore the terrifying existence of everyday, supposedly mundane animals like venomous sea snakes, stinging jellyfish, deadly rays, and saltwater crocodiles. (Saltwater. Crocodiles. So wrong.) It’s not even remotely a comfort to me to know that the world’s oceans are still for the most part an unexplored frontier, housing who knows what kind of horrors. You might think you just need to worry about the things science can verify, when the fact is that there could be shrieking eels. Kaiju. Cthulhu. You don’t know.
Barring a third or fourth viewing of Pacific Rim, though — and I mean, who wouldn’t want that? — if you’re interested in learning what oceanic monsters you should be terrified of at the moment, you’re pretty much left with Shark Week. And since the Discovery Channel seems to be getting into shrieking eel territory with their ridiculous Megalodon non-documentary, I thought I’d join the effort to bring the Shark Week tradition back to its old-school roots by telling you about an interesting, unassuming little shark that’s actually swimming around in the warm waters of the world’s oceans right now.
Cookiecutter sharks don’t look like much: they’re under two feet long, an unassuming brownish color, and used to be known by the yawn-worthy moniker of “cigar sharks.” The name doesn’t exactly seem menacing, either, like maybe they’re the peaceful bakers of the shark world, cheerfully decorating sugar cookies while the rest of their fellows tear penguins apart or whatever.
The cookiecutter shark uses its “who me? But I’m ADORABLE!” face as just one of its many weapons. (Image by NOAA.)
Don’t let cookiecutter sharks fool you, though. They’re still sharks. They’re also total assholes.
Their huge green eyes and silly-shaped mouth might look like the kind of result you’d get if you asked an anime artist to draw you a super-cute fish, but it’s all just part of their arsenal of attack weapons. What other tricks do they have up their fins, you wonder? Well, for one thing, they’re sneaky as hell. They’ve got a dark collar around their necks that makes them look like a little, tasty fish, and they’ve got bright green photophores (light-emitting organs) on their bellies — they’re the brightest of the light-up sharks known to science — which, as seen from below, practically makes the rest of their bodies invisible. This helps them get the drop on their prey.
When it comes to the actual attack, they’ve got some serious adaptations on their side. Relative to body size, they have the largest set of teeth of any known shark. The lower row of teeth actually interlock to form a surface very much like a saw blade. (When they shed teeth, as sharks are wont to do, they shed that entire row at once. And what do they do with their saw-blade row of teeth when they shed it? They swallow the entire thing, like total bad-asses, so their bodies can recycle the calcium.) They’ve also got a set of lips that act like a suction cup. Why a suction cup, you ask?
Well, the cookiecutter shark likes to aim big. Unlike a lot of other sharks, it doesn’t just go after the kind of prey that can actually fit in its mouth. Sure, it’ll eat squids and whatnot, but what it’s really known for is taking a bite out of animals much larger than it is. It ambushes them with the help of its sneaky bio-luminescent trickery, latches on with its suction-y mouth, sinks in those sizable teeth, and then twists itself while its lower jaw vibrates like an electric carving knife, slicing a neat disc of flesh away from its prey.
Scars and wounds from the cookiecutter’s bite have been found on whales, dolphins, sharks, seals, large fish, stingrays, and people. These things prey on everyone equally, including the terrifying bad-asses of the sea like great white sharks, sperm whales, and leopard seals. They’re also known to travel in schools, so an animal that falls victim to a cookiecutter attack might end up looking like a crop circle diagram. Attacks on humans are rare, though they do occasionally happen, while other species are positively plagued by cookiecutters; nearly every adult spinner dolphin off Hawaii carries the marks of the cookiecutter’s parasitic predation, and beached whales have been seen bearing hundreds of bites. Cookiecutters have also been known to chow down on submarines, underwater cables, fishing nets, and oceanographic equipment, which could be attributed to them mistaking those things for prey but personally I think they do it to be dicks.
They’re apparently elusive enough that video footage of cookiecutters in their native habitats isn’t really a thing that exists, but the BBC put together a pretty great CGI simulation that shows how their hunting technique works:
Unlike a great many of the world’s sharks, the cookiecutter isn’t endangered; it’s widespread and doesn’t face significant pressures on its population, which is sort of a good news/bad news situation on the shark conservation front. It’s like, yay, a shark species we aren’t hunting into oblivion, whooo! Bad news, it thinks the endangered sharks are delicious.