A new species of pocket shark (Mollisquama mississippiensis) that was found in the Gulf of Mexico has recently been classified. Pocket sharks get their name from the “pocket” glands behind their pectoral fins. The glands in glow-in-the-dark pocket sharks produce a bioluminescent fluid. Their bodies also generate light all over from bundles of glandular organs called photophores.
Source: Bowler, J. (2019, July 22). Scientist Just Identified a Tiny New Species of Shark That Glows in The Dark. Retrieved from https://www.sciencealert.com/researchers-have-just-identified-a-new-species-of-shark-it-has-pockets-that-glow-in-the-dark/amp?__twitter_impression=true