Atlantic sixgill shark: New shark species discovered in Atlantic Ocean

A team of scientists has identified a new shark species residing in the Atlantic Ocean. Using genetic testing, the study 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," said Toby Daly-Engel, Assistant Professor and shark biologist at the Florida Institute of Technology. Measuring up to 6 feet in length, Atlantic sixgill sharks are far smaller than their Indo-Pacific relatives, which can grow to 15 feet or longer. They have unique, saw-like lower teeth and six gill slits, as their name suggests, while most sharks have five gill slits. With their new classification, Atlantic Atlantic sixgill sharks will now have a better chance at long-term survival, Daly-Engel noted. "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 said. 

Atlantic sixgill shark – Hexanchus vitulus: 

i. Through genetic testing it has been proved that, the new shark species named “Atlantic sixgill shark” is different from the similar ones found in Indian and Pacific Oceans.ii. Hence they have not been associated with the existing species Hexanchus nakamurai. This new species is named Hexanchus vitulus.iii. The findings have been published in the journal Marine Biodiversity. The “Atlantic sixgill shark” is up to 6 feet long.iv. They feature unique, saw-like lower teeth and six gill slits. They date back to nearly 250 million years ago and are one of the oldest creatures on Earth.

Three new eel species found in Bay of Bengal : Gymnothorax pseudotile, Gymnothorax visakhaensis and Enchelycore propinqua

Context:

• Scientists have discovered three new species of eel along the northern Bay of Bengal coast in the past few months.

Other facts:

• Dark brown with white dots on the dorsal side, Gymnothorax pseudotile was discovered at the Digha coast of the Bay of Bengal.
• The other two species,Gymnothorax visakhaensis (uniformly brown) and Enchelycore propinqua (reddish brown body mottled with irregular creamy white spots), were discovered from the Visakhapatnam coast of the Bay of Bengal.

About eels:

• Eels are found mostly at the bottom of rivers and seas. Across the world about 1,000 species of eels have been identified.
• In India, the number is around 125. For species belonging to the family Muraenidae , referred commonly as Moray eels, there are records of about 200 species of which more than 30 species are found in India.

Five new species

• With these new discoveries, the Bay of Bengal coast has yielded at least five new species of eel.
• In 2016, Mr. Mohapatra and his team identified Gymnothorax indicus , an edible species.
• In 2015, a short brown unpatterned moray eel, named Gymnothorax mishrai(Bengal moray eel), was discovered from the coast of Bay of Bengal.
• The specimens of Gymnothorax pseudotile were collected in a trawl net by fishermen in the northern Bay of Bengal.