Risso's dolphin

Risso's dolphin (Grampus griseus) is the only species of the genus Grampus in the family Delphinidae (dolphins). Some of the most closely related species to these dolphins include: pilot whales (Globicephala spp.), pygmy killer whales (Feresa attenuata), melon-headed whales (Peponocephala electra), and false killer whales (Pseudorca crassidens). These dolphins grow to be about 10 ft in length and can be identified by heavy scarring that appears white. They are located worldwide in cold to temperate waters, but most typically found along continental shelves due to their eating habits. Risso's dolphins have a diet that contains primarily cephalopods. They are able to search for prey at various depths due to their ability to reach depths of almost 600 m (2,000 ft). Individuals typically travel in pods ranging from 10 to 50 dolphins, with which they form tight social bonds. Like most marine species, Risso's dolphins suffer from anthropogenic disruptions to the environment. Pollution, both from noise and plastics, is a common cause of higher mortality rates. Many can be, or have been, affected by entanglement in fishing nets and whaling. Risso's dolphins are currently protected in the United States, but they are still hunted in other parts of the world.