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 Risso's Dolphin (Grampus griseus)




Risso's Dolphin | Grampus griseus photo
Risso's Dolphins off Pt. Vicente, Southern California

Photograph by Cybele May. Some rights reserved.  (view image details)

Risso's Dolphin | Grampus griseus photo
Risso's Dolphins off Pt. Vicente, Southern California

Photograph by Cybele May. Some rights reserved.  (view image details)

Risso's Dolphin | Grampus griseus photo
Photographed on boat trip from Avila Beach, California.

Photograph by Mike Baird. Some rights reserved.  (view image details)

RISSO'S DOLPHIN FACTS

Description
Risso's Dolphin is pale gray with a blunt bulbous head and large dorsal fin. Adults are covered with pale scratches and scars. Juveniles are darker and have no scarring. The flippers are long and pointed. There is a groove from the tip of the snout to the blowhole. The blowhole is quite large and slightly to the left of the midline. The eye is small and often surrounded by a dark grey or black patch. Risso's Dolphin has no teeth in the upper jaw and an average of 3 or 4 on each lower jaw.

Size
length: 4m - 4.3m. Weight: 300kg.

Environment
Risso's Dolphins are found in the open ocean, usually on the seaward side of the continental slope.

Food
octopus, squid, cuttlefish, krill

Breeding
Little is known of their breeding, Calves are about 1.1m - 1.5m at birth. The gestation period is about 12-13 months.

Range
All temperate and tropical oceans

Conservation Status
The conservation status in the 2004 IUCN Red List of Threatened Animals is "data deficient".

Classification
Class:Mammalia
Order:Cetacea
Family:Delphinidae
Genus:Grampus
Species:griseus
Common Name:Risso's Dolphin