Cookiecutter shark

The Cookiecutter shark (also known as the Cigar shark or Luminous shark) is a small rarely-seen shark which often glows green and grows up to 20 inches long. It has been found about 3,300 ft. below the surface of the ocean. Cookiecutter breeding is unknown.

The Cookiecutter shark derived its name from its habit of removing small circular chunks of flesh from whales and large fish. It is hypothesized that the shark seizes its much larger prey with its jaws, then rotates its body to achieve a highly symmetrical cut.

It has been proposed the luminescent patch on the shark's underbelly deceives the shark's prey, smaller predatory fish (like tuna), into thinking the shark is an even smaller fish. When the predatory fish tries to strike at the shark, the shark strikes back, scoring itself another meal [1]. This is the only known instance whereby a bioluminescent lure is created by the abscence of luminescence (contrast with anglerfish).

Cookiecutter sharks reproduce through aplacental viviparity in the same way as great white sharks. Little else is known about their reproduction.

External links

• Glow in the dark shark has killer smudge by S. Milius
• Australian Museum Fish Site
• Cookie Cutter photo essay