Cut to the Quick by Cookiecutter Sharks

posted: 04/11/12
Read more Read less
Cookiecutter Shark
More to Explore From HowStuffWorks.c

Cookiecutter sharks have lots of nicknames. "Cigar shark," for example, comes from their appearance. They're rather small as far as sharks go — not more than about 2 feet (61 centimeters) long — and pale in color except for a dark wraparound band over the area around their gills.

Another of the cookiecutter shark's nicknames is "luminous shark." That's because cookiecutter sharks, being deep-sea dwellers, use bioluminescence as a survival technique. Light-emitting organs called photophores are located all around the sharks' bodies, but they're especially concentrated on the underside. The one notable place the photophores are absent is on the dark collar — this makes larger prey think the cookiecutters are smaller than they really are. The light organs also provide camouflage through a strategy called counterillumination, or mimicking sunlight, so the sharks are harder to see from underneath.

So if it looks like a luminous cigar, what's with the name? It all has to do with how they eat. Cookiecutter sharks are parasitic in nature, meaning they feed off other creatures. They aren't deadly, though — they just take a big enough bite to get their fill.

First, the cookiecutter shark's deceptively small appearance lures a predator. Once it's close enough to strike, the shark opens its jaws wide and latches on, forming a powerful suction seal. When it's firmly secured, the shark uses a combination of spinning and sawing to chew out a perfectly circular cone of flesh — just like a cookiecutter.

More on
Shark Week