pocket shark
Courtesy NOAA

You are in the middle of the Gulf of Mexico, 8 years ago, doing research on sperm whales In a net brought up are various fish, shrimp , and a weird looking small creature about 5 1/2 inches long. You are curious about this small creature , and stick it in the freezer for later research. And forget about it.

A few years later, you are “spring cleaning” and find the small creature in the freezer. After some research, you find it is a new species, you name it Mollisquama mississippiensis, or a new species of Pocket Shark.

Roughly, that’s how the story goes.

The first Pocket Shark was found in the 80s in the Southeast Pacific Ocean. It was a female 16″ long. These species are different except for one common thing: the real reason they are called pocket sharks. They are called pocket sharks because it actually references a unique gland on the shark just above where the pectoral fins meet the body that no other type of shark has. Nobody is sure what the pocket gland is used for, but scientists hypothesize that it could be used to secrete pheromones and attract mates.

Both species are deep water species. Both are bioluminescent i.e. they glow in the dark. They are the only two Pocket Sharks recorded to date.

Full Scientific report