Risso’s Dolphin

Grampus griseus


10-13 feet (3-4 m)


650-1,100 pounds (300-500 kg)


Prefer offshore habitats in warm temperate and tropical waters in both hemispheres


Unknown worldwide, approximately 15,000-30,000 off the coast of California


Risso’s dolphins are one of the larger members of the dolphin family. They are dark gray with extensive white scarring caused by encounters with their main prey item, squid, which have sharp hooks in their tentacles. The scarring can also be caused by bites from other Risso’s dolphins.

Risso’s dolphins typically travel in groups of 3-30 animals although megapods of more than 1,000 have been witnessed. Little is known about this species because they are typically found so far offshore.