(CNN) Sharks are known to stalk and sniff out prey before they attack. But all this newly discovered shark species has to do is glow in the dark, and the prey comes to them.

The 5 1/2-inch American Pocket Shark is the first of its kind to be discovered in the Gulf of Mexico, according to a new Tulane University study . It's less fearsome than it is wondrous.

Scientists stumbled upon a teeny male kitefin shark in 2010 while studying sperm whales in the Gulf. It wasn't observed again until 2013, when National Oceanic and Atmospheric Administration (NOAA) researcher Mark Grace found it in a pool of less luminous specimens.

It's only the second pocket shark ever captured or recorded, Grace said in a statement. The other was found in 1979 in the east Pacific Ocean.

"Both are separate species, each from separate oceans," he said. "Both are exceedingly rare."