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| credit: M. Doosey |
That favorite summertime box office fear, the shark, is not only a humongous assassin of the open ocean, but also exists in a pocket size version big enough to eat only small fish and invertebrates. A diminutive denizen of the Gulf of Mexico is about five inches long, and researchers say it may glow in the dark!
Mollisquama mississippiensis, or the American pocket shark, was recently described for science and named after the biologically rich Mississippi Basin region it inhabits. It was caught in 2010. Only one other species of miniature shark,
M. parini, captured from the ocean was caught in the Pacific in 1979. Sharks are ancient species that have changed little over eons. Their obvious diversification to inhabit various ecological niches is testament to their evolutionary success story. Pocket sharks are extremely rare and are named so because of gland openings found behind each pectoral fin.
The new discovery, made by researchers from NOAA while searching the eastern Gulf to determine what sperm whales eat,
is published in Zootaxa. Mississippiensis has photophores, luminescent organs, covering its body. Scientists believe this may help the fish luminescent in the darkness of the deep ocean. Science knows very little about the much exploited Gulf of Mexico and the newly described miniature shark is an example of what more unknown unknowns still exist in its depths.
