A tiny shark which glows in the dark and squirts luminous liquid was found in the Gulf of Mexico nearly 10 years ago and now scientists have discovered it be a new species.
The specimen – a 5.6-inch (14cm) newborn male shark –was collected during a 2010 survey to find out what sperm whales eat. Then in 2013, scientists noticed it to be unusual. Since then, it has taken them years to test and prove for certain the shark species had never been recorded before.
It has been named the American pocket shark, Mollisquama mississippiensis, not due to its diminutive pocket-size but because of the pocket-like pouches near its front fins. Researchers believe the shark uses its pouches to squirt a fluorescent fluid to help conceal it from prey or predators.
The specific details of this new species are described in the journal Zootaxa by Mark Grace of the NMFS Mississippi Laboratories of the National Oceanic and Atmospheric Administration (NOAA), and Henry Bart and Michael Doosey of the Tulane University Biodiversity Research.
Grace said:
I’ve been in science about 40 years and I can usually make a pretty good guess about a marine animal’s identity. I couldn’t with this one.
He turned to experts at Tulane University, the American Museum of Natural History in New York, and the Florida Museum of Natural History, at the University of Florida.
The only other pocket shark known to science is a 16-inch adult female caught in the Pacific Ocean off Peru in 1979 and is now housed at the Zoological Museum in St Petersburg, Russia. It also has a pouch next to each front fin but the scientists at that time were unable to determine the function for them. But now with this one, they figured it out.
European expert, Julien Claes, did a cellular dissection of part of the pocket tissue to confirm its function. He discovered that the muscular glands are lined with pigment-covered fluorescent projections, indicating they squirt luminous liquid. The shark also has clusters of light-emitting cells dotted over its stomach.
A 2015 paper identified the shark as the second of its kind, but it took four more years of studying the creature to be 100% sure that it really was a new species.
Bart 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.
