Indian Humpback Dolphin

The Indian Ocean humpback dolphin is a medium-sized dolphin of coastal waters from southern Africa to western Indochina, including East Africa, the Middle East and India. It was once lumped with the Indo-Pacific humpback dolphin, but a 2014 study showed them to be separate species. It measures 2–2.8 m and weighs 150–200 kg. A fatty hump on the back distinguishes it from the Indo-Pacific species, and it is generally dark grey, with young animals darker above than below (Wikipedia, general species account).

Most animals stay in water shallower than 20 m. It lives in groups that average about a dozen, although group size varies widely and some exceed 100. The diet is mostly sciaenid fishes, cephalopods and crustaceans. Living in shallow coastal water exposes it to pollution, by-catch, vessel strikes and noise, and calf and juvenile mortality from such disturbance is very high (Wikipedia, general species account). The cached account gives nothing specific to India.