Risso's dolphin

It has a stocky body with a fairly rounded snout; the head has a marked vertical crease which, running from the blowhole down to the upper jaw, divides it into two parts.  The dorsal fin is strongly falcate.

At birth the body is light grey on the back and white on the belly, on the pectoral fins and often on the snout, where an anchor-shaped patch can be seen. The colouring of Risso's dolphin darkens as it grows until it becomes almost completely black, except for the underside, which stays pale. The back and flanks show scratches caused by interactions with other Risso's dolphins.

The more scratches it has, the older the animal is; indeed, some individuals have an almost completely white back. The dentition of this species is rather unusual: it has no teeth in the upper part of the mouth and at most 7 in the lower part. Risso's dolphin reaches 4 m in length and 700 kg in weight.

It normally swims very fast and is an excellent breath-hold diver, reaching depths of around 500 m on dives lasting about 30 minutes.

It is often seen in three postures: head raised out of the water, tail raised out of the water, and tail slapping the water while facing the observers. Risso's dolphins usually live in groups of 10-50 individuals of all ages and both sexes; they live in the open sea but may also come close to the coast in search of food. 

It feeds mainly on cephalopods.