Pocket Shark: Second Specimen Of Ultra-Rare Species Discovered

An ultra-rare pocket shark, a member of a species only observed once before, has been discovered amidst a group of fish collected for scientific study in 2010, proving that the unusual animal can be found swimming off the southern coast of the United States.

The first pocket shark ever discovered was found 36 years ago, according to the Associated Press, off the coast of Peru. That specimen currently resides in a Russian museum, and until recently, it was the only pocket shark ever observed. Now, a surprised group of scientists have discovered a second specimen amidst a collection of fish gathered in 2010 from the Gulf of Mexico as part of a study into sperm whale feeding, which have been frozen for the past few years while they await classification.

Described as a cross between a kangaroo and a shark, the species is characterized by twin pockets next to its fins, which researchers are currently at a loss to explain. Biologists Mark Grace and Michael Doosey have speculated that the pockets are possibly used to secrete pheromones or glowing fluid, though neither assertion has been proven.

Grace, the National Oceanic and Atmospheric Administration fisheries biologist who uncovered the pocket shark specimen, asserted that he wasn’t sure what the animal was when he first thawed it out.

“That pocket over on the pectoral fin, I had never seen anything like that on a shark,” he recalled.

Doosey, who co-authored the study in which the shark was identified, according to NOAA, noted that the predator resembled a small whale. At 5.5 inches long, the specimen was a juvenile male, likely only a few weeks old, as evidenced by umbilical scars on its body. Its pockets cover a full four percent of its body, a trait that it shares with few other animals.

Scientist finds a pocket shark—the 2nd specimen ever found. Why is it called a pocket shark?: http://t.co/qQ8oo2jgrW pic.twitter.com/Co1xywCt50

— Rich Press (@Rich_NOAAFish) April 23, 2015

The Russian pocket shark specimen is far different than the one identified by Doosey and his fellow scientists. A female that measures 17 inches, it has led researchers to believe that adult female pocket sharks may grow to be larger than males. It very nearly represented the only specimen in existence also, as the lab where the Gulf pocket shark was kept lost power several times, shutting off the freezer that preserved it.

Earlier this year, another rare specimen was captured, when a goblin shark was caught in Australia. As the Inquisitr previously reported, the unusual shark is poorly understood, though it has been observed far more than the pocket shark.

[Image: Michael H. Doosey/Tulane University via AP]