Cabrillo Marine Aquarium

Risso's dolphin

Grampus griseus


Fun Facts

    Adult Risso's dolphins bodies are typically heavily scarred, while calves have little or no scarring

    Risso's dolphins are also known as Grampus




The Risso's dolphin is a type of marine mammal that lives in offshore waters.  Risso's dolphins occur worldwide in temperate and tropical waters. The robust body is dark gray with extensive white scarring. They can reach lengths of approximately 8.5 to 13 feet (2.6-4 meters).

Risso's dolphin feed almost exclusively on squid but at times also eat fish and krill. Feeding occurs mainly at night when their prey is closer to the surface. They are capable of diving to at least 1,000 feet (300 m) and can hold their breath for about 30 minutes. The gestation period is approximately 13 to 14 months. Females become mature at ages 8 to 10, and males at age 10 to 12. Females reproduce typically every 2 years.

To learn more about Risso's dolphins and their relatives visit the Whales & Dolphins Room at the Aquarium.