This new shark species might be having an identity crisis, as it looks exactly like a miniature sperm whale. The Mollisquama mississippiensis, a 5.5-inch-long shark, was first discovered in the Gulf of Mexico in 2010. While it was originally thought to be the same species as a similar tiny shark found in 1979 (the Mollisquama parini, or pocket shark), research has revealed that the M. mississippiensis, which resembles a small sperm whale, is a different species entirely.
Since the research team didn’t want to dissect the animal, given its rarity, they studied it using advanced, non-invasive technologies such as a dissecting microscope and high resolution CT scans. They also had the shark imaged by the European Synchrotron Radiation Facility in France. After extensive evaluation, the researchers observed that the new shark specimen had fewer vertebrae than the one discovered in 1979, as well as light-producing organs called photophores, which may facilitate predatory behavior by making sharks nearly invisible from below.
Researchers landed on the name M. mississippiensis, or the American pocket shark. Pocket sharks are not dubbed as such because of their size, but in reference to the pocket glands the animals have on each side near the gills.
Mark Grace, a biologist from the National Oceanic and Atmospheric Administration, said, “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.”