Shark Week 2019: New Tiny Sharks That Glow in the Dark Discovered by Scientists

Just ahead of Discovery's Shark Week 2019 premiere, the science community is swimming following the discovery of a previously unknown shark species. According to a new Tulane University study, scientists discovered the American Pocket Shark, a tiny species of the toothy marine animals that glow in the dark, in the Gulf of Mexico.

New shark species!@NOAA says it's a tiny subset of sharks known as the American Pocket Shark.
The sharks have a light-emitting pocket organ near their front fins.
Researchers: only 2 sharks ever captured.
1 caught in the Gulf of Mexico 9 yrs ago.
Other- in the Pacific in 1979. pic.twitter.com/x3V5eaf3yF

— Amanda Russo (@Amanda_Russo12) July 22, 2019

The pocket-sized creature, discovered during a 2010 survey to find out what Gulf of Mexico sperm whales eat and again observed in 2013, measures just 5.5 inches long, or 14 centimeters, and has pocket-like pouches behind its pectoral fins. Those "pockets" contain glands that produce a bioluminescent fluid. The tiny specimen also has photophores, or light-producing organs, all over its body, meaning that it glows in the dark.

"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 - especially its deeper waters - and how many additional new species from these waters await discovery," Henry Bart, director of the Tulane Biodiversity Research Institute, said, Science Alert reports.

The American pocket shark is only the second pocket shark to be captured and recorded, according to National Oceanic and Atmospheric Administration (NOAA) researcher Mark Grace. In 1979, the first pocket shark, an adult female, was discovered off the coast of Chile in the Nazca Submarine Range. It measured around 16 inches long, or 40 centimeters and was named Mollisquama Parini.

"In the history of fisheries science, only two pocket sharks have ever been captured or reported," Grace said. "Both are separate species, each from separate oceans. Both are exceedingly rare."

The Independent reports that differences between the two tiny sharks include a possible pressure-sensitive organ that the new species may use to detect motion hundreds of feet away. There are also differences in their teeth and the species discovered in 2010 possibly has as many as 10 fewer vertebrae than the pocket shark discovered in 1979.

The exciting discovery comes amid an equally as exciting time for shark fanatics. Beginning on Sunday, July 28 and running until Sunday, August 4, Discovery Channel will be airing its 31st edition of Shark Week, the week-long programming slate filled to the brim with nothing but shark content.

This year's schedule is set to make a big splash, featuring 18 new specials as well as the first original film on the network, titled Capsized: Blood In The Water and starring Josh Duhamel.

Shark Week kicks off Sunday, July 28 and continues through Sunday, Aug. 4, only on Discovery. You can see the full list of this year's programming by clicking here.