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Head of a cookie cutter shark. Credit: Karsten Hartel- Marine Fisheries Review
Few creatures are foolhardy enough to take on a great white shark — much less try to lure one in. Yet a shark that’s no longer than your arm has been known to do just that.
The cookiecutter is among the smallest of all sharks. Adults are only about 16 to 20 inches long. They inhabit warm waters around the world, mostly near islands.
The cookiecutter has big, fleshy lips and two rows of teeth. Those on the top are small and pointed, while those on the bottom are big and triangular. Each row of teeth is a complete unit; when they come out, the shark swallows the entire row, adding some calcium to its diet.
Sometimes, the shark uses those teeth to nab prey that it eats whole, such as squid. At other times, though, it uses its lips to attach to a larger animal, such as a dolphin, whale, seal — or even another shark. It then grabs the victim with the top teeth, and digs in with the bottom teeth. The little shark then twists its body all the way around, cutting out a circular patch of flesh — like a cookie. That doesn’t usually kill the larger animal, but it sure does smart.
The cookiecutter may even lure in the larger prey. Its underside is covered with organs that produce green light. So seen from below, the shark blends in with the lighter waters above — except for a small, dark patch near its head, which a predator may think is a small fish. The larger animal then swoops in for a snack, only to have the cookiecutter latch on and grab its own snack — a fleshy morsel shaped like a cookie.
