Ivy Baremore/MarAlliance via Live Science .

Scientists Find New Species of Sixgill Shark Cruising the Atlantic

The sea has yielded yet another surprise: scientists have discovered a new species of shark that calls the Atlantic Ocean home.

The deep-sea dwelling Atlantic sixgill shark was believed to belong to a global species of sixgill shark called Hexanchus nakamurai. However, a genetic analysis by has revealed that it is, in fact, a novel species. Marine biologists have named the new discovery Hexanchus vitulus.

 Florida Institute of Technology shark scientist, Toby Daly-Engel, told LiveScience:

"We showed that the sixgills in the Atlantic are actually very different from the ones in the Indian and Pacific Oceans on a molecular level, to the point where it is obvious that they're a different species even though they look very similar to the naked eye."

The newest addition to the sixgill family (named for their six gill slits, where most sharks have only five), the Atlantic sixgill, reaches a length of up to six feet, much smaller than the 15-footers that swim in Indo-Pacific deep waters. Remarkably, the largest species of sixgill, the bluntnose sixgill (Hexanchus griseus) reaches lengths of up to 26 feet.

sixgill shark

The bluntnose sixgill is the largest species of sixgill shark, reaching lengths of up to 26 feet. Photo courtesy of NOAA Ocean Explorer/flickr.

Scientists compared mitochondrial DNA (DNA passed on through the female line) of deep ocean Atlantic sixgills with Indian and Pacific sixgills. The results showed a clear distinction between groups of sixgill shark species. The sharks from Belize, the Bahamas, and the Gulf of Mexico were genetically different from the sharks from Japan, Madagascar, and other areas in the Indo-Pacific. A new shark species was discovered.

"Because we now know there are two unique species, we have a sense of the overall variation in populations of sixgills...We understand that if we overfish one of them, they will not replenish from elsewhere in the world," said Daly-Engel.

The researchers published their shark diversity findings in Marine Biodiversity and you can check it out here.

What do you think of this new shark species discovery? Let us know in the comments section!

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