In 1979, researchers in the Eastern Pacific Ocean scooped up a small, never-before-seen shark with distinctive pockets near its gills. Another “pocket shark,” as the animal was dubbed, was not seen again until 2010, when a National Oceanic and Atmospheric Administration ship found one in the Gulf of Mexico. But as Mindy Weisberger reports for Live Science, a new study has revealed that the two specimens do not belong to the same species—highlighting just how much scientists have yet to discover about the creatures that live in the mysterious deep.
Published in the journal Zootaxa, the paper describes an unusual shark that was discovered during a scientific survey of the Gulf of Mexico, while scientists were researching the feeding behaviors of sperm whales. The researchers used sonar to track the whales as they dove to 3,000 feet, then used nets to drag up prey from the area. Among those samples was a male pocket shark, which was frozen for later analysis.
Then, in 2013, NOAA biologist Mark Grace was processing specimens collected from these deep waters when he came across one animal that he could not identify.
“I knew it was a species of shark,” Grace said in 2015. “But I’d never seen anything like it before.”
source: Smithsonian.com By Brigit Katz