First omnivorous Shark species identified

New Delhi : Scientists claim that they have identified the first known omnivorous shark species which graze seagrass along with marine fishes, crabs and snails. The findings have overturned the concept that all sharks are only meat-eaters.

The details of study and findings are published in the journal Proceedings of the Royal Society B. Researchers from the University of California, Irvine in the US found that bonnethead sharks's diet consist of seagrass. They are Omnivores species which feed on a variety of food of both plant and animal origin. 

The bonnethead shark is commonly found in the shallow waters of the Western Atlantic, and the Gulf of Mexico.

The researchers analysed the sharks' dietary habits include the flowering marine plant that forms subsea meadows in some coastal waters. They retrieved sea grass from Florida Bay and hauled it back to the lab where they re-planted it.

As the experimented seagrass took root, the researchers added sodium bicarbonate powder made with a specific carbon isotope to the water. This was taken up by the seagrass, giving it a distinctive chemical signature. The researchers then caught five bonnethead sharks and brought them to the lab.

They were fed on a three week diet of the seagrass and squid. The scientists ran a series of tests on the sharks.

These showed that they successfully digested the seagrass with enzymes that broke down components of the plants, such as starch and cellulose.

Researchers say that Shark has strong acid in the stomach which helps them to weaken the plant cells so the enzymes can have their digestive effects.