Tiny, glow-in-the-dark shark discovered in Gulf of Mexico

The 5.5-inch fish has been identified as the American pocket shark and is the first of its kind found in the Gulf. It secretes a luminous fluid from two small pockets on each side near the gills, which could help it attract prey and conceal itself to make hunting easier, according to a new study from scientists at Tulane University

The only other specimen of its kind was found in the eastern Pacific Ocean in 1979, Tulane researchers said.

"The fact that only one pocket shark has ever been reported from the Gulf of Mexico, and that it is a new species, underscores how little we know about the Gulf," Tulane Biodiversity Research Institute Director Henry Bart said in a statement on the discovery.

The new species was caught in February 2010 during a study of sperm whales in the Gulf of Mexico and was described in the animal taxonomy journal Zootaxa.

“In the history of fisheries science, only two pocket sharks have ever been captured or reported,” study author Mark Grace said.

“Both are separate species, each from separate oceans. Both are exceedingly rare,” Grace said.

Researchers recorded notable difference between the shark found in the Pacific and the one found in the Gulf, including fewer vertebrae and numerous light-producing photophores.