Tiny, Adorable and 'Exceedingly Rare' Species of Pocket Shark That Glows in the Dark Discovered by Scientists

Scientists have identified a tiny new species of pocket shark from the Gulf of Mexico which secretes a glow-in-the-dark liquid as a method to attract prey.

The find is significant because this is only the second member of the genus (group of species) Mollisquama ever to be identified, according to a study published in the journal Zootaxa.

The identification of the new species—dubbed the American Pocket Shark (Mollisquama mississippiensis)—was based on the analysis of a single 5½-inch-long male specimen caught in the Gulf in 2010.

Researchers from Tulane University in Louisiana used several techniques—such as X-ray imaging and high-resolution CT scans—to examine the specimen and determine that it was a different species to the only other pocket shark ever reported (Mollisquama parini) which was caught in the Eastern Pacific Ocean in 1979.

"In the history of fisheries science, only two pocket sharks have ever been captured or reported," Henry Bart, director of the Tulane Biodiversity Research Institute, said in a statement.

"Both are separate species, each from separate oceans. Both are exceedingly rare," he 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—especially its deeper waters—and how many additional new species from these waters await discovery."

M. mississippiensis and M. parini display similar characteristics in the sense that they both feature two relatively large "pockets" near their front fins and gills. In the paper describing the latter, the researchers say that these pockets contain glands that release a luminous, fluid that attracts prey animals which are then conveniently distracted, giving the shark the perfect opportunity to pounce.

But despite their similarities, the two species also display notable differences, according to the Tulane scientists.

For example, M. mississippiensis has fewer vertebrae than its Pacific relative and also features numerous light-producing organs known as photophores which are found all over its body.

Pocket sharks belong to the larger animal family known as Dalatiidae or "kitefin sharks." Members of this family—which tend to measure less than 6.6 feet in length—are found around the world. They are characterised by long, thin, tube-shaped bodies featuring strong jaws containing a host of sharp teeth.

The original pocket shark specimen was caught off the Chilean coast at a depth of around 1,080 feet, Sci-News reported. This individual—which measured 16 inches in length—initially led researchers to believe that pocket sharks were found in the Pacific Ocean alone. However, the latest discovery indicates that their distribution is actually much more widespread.

pocket shark
The newly identified American Pocket Shark was first discovered in the Gulf of Mexico in 2010. Mark Doosey