A “glow-in-the-dark” shark species found in the Gulf of Mexico uses bioluminescent fluid to attract its prey, scientists have found. Researchers first chanced upon the Mollisquama mississippiensis, or the American Pocket Shark, in 2010 while observing the feeding of sperm whales in the Gulf of Mexico, according to a new Tulane University study quoted by ABC News. The study was published in the animal taxonomy journal Zootaxa.
Mark Grace of the National Marine Fisheries Service Mississippi Laboratories of the National Oceanic and Atmospheric Administration noticed its special features while examining the collected specimens for a NOAA survey in 2013, the Tulane University said in a statement.
The 5.5 inch shark, a subspecies of the kitefin shark, releases a bioluminescent fluid to attract its prey, according to the study.
The only other known specimen of its kind was captured in the eastern Pacific Ocean in 1979 and is housed at the Zoological Museum in St. Petersburg, Russia, ABC News reports. However, both are "separate species, each from separate oceans," Grace 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," said Henry Bart, director of the Tulane Biodiversity Research Institute.
Both species are "exceedingly rare," Grace said, explaining that notable differences include fewer vertebrae in the shark and numerous light-producing photophores that cover much of the body in Gulf shark.
Both, however, have two small pockets on each side of gills that produce luminous fluid.
Other glow-in-the-dark sharks previously discovered include the Scyliorhinus rotifer, a chain catshark, and the swell shark, which has a "twinkling" pattern, according to Live Science.
