It's only the second pocket shark ever captured or recorded, Grace said in a statement. The other was found in 1
"Both are separate species, each from separate oceans," he said. "Both are extremely rare."
A glow-in-the-dark ocean organism is hardly unique. NOAA estimates about 90% of the animals that live in open water are bioluminescent, although research on deep sea creatures is scant.
An animal's glow is triggered by a chemical reaction that emits light energy, according to the Smithsonian National Museum of Natural History. Organisms light up to attract a mate, warn an attacker to stay away or, in most cases, make a meal out of a smaller swimmer.
Remember the fanged fish with the glowing antenna that terrified Marlin and Dory in "Finding Nemo?" It's called a black seadevil, and it's very real and very terrifying. True to its name, it lures its prey towards its jaws by dangling and bioluminescent spine from its top of its head, says the Monterey Bay Aquarium Research Institute.