World’s rarest shark will fit in your pocket

By: Ashley Gustafson


pocket-shark-1aIt is one massive understatement to say that there is still a great deal to learn about the oceans and all the species that call it home.It is nearly a daily occurrence that new species are being discovered in the deep, mysterious waters of the ocean floor. These new discoveries are not only exhilarating but also give researchers and scientists a few more pieces of the puzzle which is the world’s oceans. Just a few days ago one of these unusual discoveries occurred at the Tulane University Biodiversity Research Institute in New Orleans, Louisiana. A very small and extremely rare species of shark, commonly called the pocket shark, was discovered in the holdings of a NOAA lab in Pascagoula, Mississippi. The pocket shark was collected about 190 miles offshore coastal Louisiana while the NOAA Ship Pisces was on a 2010 mission to study sperm whale feeding behaviors. When Mark Grace of NOAA Fisheries Pascagoula Mississippi Laboratory found this rare shark in their holdings, he recruited Tulane University researchers Michael Doosey and Henry Bart as well as the NOAA Ocean Service genetics expert Gavin Naylor in order to get a closer look at the surprise specimen.

While the common name of this species is the “pocket shark” its scientific name is Mollisquama sp. as published by the international journal of taxonomy, Zootaxa. While the word “shark” brings images of large, fierce predators to mind, the pocket shark found was only 5 and a half inches long so the name “pocket” seems appropriate as it would easily fit in a pocket. However, the common name actually comes from an opening behind the animal’s pectoral fin that looks like a pocket. The function of this open “pocket” is unknown and yet just another feature of this mysterious shark scientists hope to learn more about through this new discovery.

This elusive shark is only the second recorded in modern history. The first specimen was found off the coast of Peru 36 years prior. This new pocket shark is a newborn male who displays an unhealed umbilical scar. With the first specimen in mind, this new discovery raises many questions like where are mom and dad? How did they get all the way up to the gulf? Are there others? And so on. With these questions in mind, a tissue sample was collected from the new specimen and sent to the extensive specimen collection of Tulane University’s Biodiversity Research Institute. Scientists there were then able to confirm that this specimen belongs to the genus Mollisquama (as proposed). From this confirmation, Naylor was able to further disclose that pocket sharks are closely related to kitefin and cookie cutter species both which are part of the shark family Dalatiidae. From this connection, Naylor suspects that pocket sharks can remove an oval plug of flesh from their prey when hungry. Their prey most likely consists of marine mammals, large fishes, and squid.

It is without uncertainty that this discovery is a special one with exciting opportunity. This specimen will be part of the Royal D. Suttkus Fish Collection at Tulane University’s Biodiversity Research Institute in Belle Chasse, Louisiana so that is can be furthered studied. Compared to its 1979 counterpart, this new specimen has several more glands along the abdomen that weren’t previously noted in the former taxonomic description. This is exciting news, as it gives scientists more on an otherwise nonexistent species. It is so exciting in fact that the partners at the Smithsonian Natural Museum of Natural History in Washington D.C. and the American Natural History Museum in New York City have already contributed to research of this specimen. I know that before this article I had never heard of the Pocket Shark, nor did I imagine there was such an animal. That is the amazing thing about the ocean; as much as we know there is still even more that we have left to uncover.