Common name: Cookiecutter sharks

Scientific name: "Isistius spp"

Size

Cookiecutters are one of the smaller species of sharks. They can reach lengths up to 50 cm (up to 19 inches).

Cookiecutter Highlights:

These are my favorite species of sharks because of the way they eat. A cookiecutter shark uses its lips to attach to the prey. It then spins quickly, using its teeth to bore out a piece of the animal's flesh. It leaves a nice round hole in the prey - like someone came along with a cookiecutter. It's teeth are bigger compared to it's body size than most sharks. In fact, their teeth are twice the height compared to body size than a great white. A cookiecutter shark preys (or snacks on) megamouth, basking and whale sharks. It may also snack on tuna, marlin, beaked and other whales and dolphins. Cookiecutter sharks are found in temperate and tropical seas.

A Sneaky Silhouette.

Like other deep-sea animals, cookiecutters are "bioluminescent."  (Think of a firefly -- it's bioluminescent, too. ) On the bottom (belly-side) of the cookiecutter glows from chin to tail.  But, it doesn’t stand out, like a flashlight in a dark room. The “glow” is actually a type of camouflage. If you were underneath the shark, the bioluminescent parts blend into the sunlight or moonlight above, helping the shark disappear into the sea. Except....the cookiecutter shark has a dark band of skin under the jaw without bioluminescence. Some call this patch a “collar.” Because the collar doesn’t shine it is obvious from below. The collar leaves a small silhouette predators can see.

    What good is camouflage that partly works? It’s a trick. Bioluminescence expert Dr. Edith Widder, from the Harbor Branch Oceanographic Institution, thinks this seemingly illogical camouflage is actually a lure to trick predators into coming closer. How? The predator, swimming underneath the cookiecutter, only sees the small collar. Thinking it has found dinner it speeds in for the kill. But when it gets to the would-be snack....twist and scoop! The tables have been turned and the ex-predator becomes the cookiecutter’s prey. Now that’s sneaky.

    Dine and dash. Few animals are safe from the bite and run attack of a cookiecutter. Hunting this way is a masterstroke. Think about it. If you were a cookiecutter shark you wouldn’t have to chase anything. You wouldn’t have to fight with prey when it resists being eaten. And, like pizza delivery, because of your bioluminescent trick the food comes to you. By the time your victim realizes something is wrong, you’re already swimming away, with a most excellent seafood snack. It’s brilliant.

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