According to a latest report, a team of scientists has identified a new shark species residing in the Atlantic Ocean. The study, published in the journal Marine Biodiversity, confirmed that the new species, named the "Atlantic sixgill shark", is different than its counterparts in the Indian and Pacific Oceans.
"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," Toby Daly-Engel, Assistant Professor and shark biologist at the Florida Institute of Technology said.
The Atlantic sixgill sharks measure up to 6 feet in length and are far smaller than their Indo-Pacific relatives, which can grow to 15 feet or longer. As the name suggests, these new species of sharks have unique, saw-like lower teeth and six gill slits. But, one can find only five gill slits in most sharks.
Daly-Engel said that Atlantic sixgill sharks will now have a better chance at long-term survival especially after their new classification.
"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," she added.
These Atlantic sixgill sharks are among the oldest creatures on Earth with ancestors dating back to over 250 million years, well before dinosaurs. However, as they reside at extreme ocean depths, sometimes thousands of feet below the surface, has made them especially challenging to study.
The researchers determined that there are enough genetic differences between what had long been considered a single species, Hexanchus nakamurai, to rename the Atlantic variety Hexanchus vitulus using 1,310 base pairs of two mitochondrial genes.