Category of Organisms Marine Mammals
Kingdom Animalia
Phylum/Division Chordata
Class Mammalia
Order Cetacea
Family Delphinidae
Genus Grampus
Species griseus
Binomial Name
Grampus griseus
Author G.Cuvier, 1812
Common Name Risso's dolphin, Grey Dolphin, White-Head Dolphin
Local Name  
Size Range
Length is typically 10 feet (3 m), although animals have been recorded up to 12.5 feet (3.8 m).  This species weighs 300-500 kg (660-1100 lbs), making it the largest species called "dolphin"
Environment/Habitat
Risso’s dolphins inhabit deep oceanic and continental slope waters, generally 400-1,000 m deep (Baird 2002; Jefferson et al. 1993), mostly occurring seaward of the continental slope. They frequent subsurface seamounts and escarpments, where they are thought to feed on vertically migrant and mesopelagic cephalopods.
Importance/Value
 
Resilience
 
Endemic No
Found in Marine Park No
Found in Malaysia Yes
Distribution
 
Morphology/Character
Mouth slants upwards. Flippers long, narrow crescent-shape, with pointed ends. Tips of fluke arrow-shaped and curved backwards. Only species in the family without teeth in upper jaw, only has 4-14 teeth in front of lower jaw, older animals often toothless (typical and feeder). Colouration varies with age and gender. Dark-grey to grey-black, ventrally paler. Scratches and scar more numerous as animal ages, thereby turning almost-white. Only dorsal fin, fluke and flippers remain dark. White, anchor-shaped path on thorax. Males more scarred than female. Scars inflicted by teeth of rival (intraspecies aggression), as well as the beaks of cephalopods. Patterns of scars used to identify individuals. Newborn calves are dark-grey, no scars.
Biology
Risso's dolphins feed on crustaceans and cephalopods, but seem to prefer squid. Squid bites may be the cause of at least some of the scars found on the bodies of these animals

Miscellaneaous
 
Status in IUCN Red List Least Concern (LC)
Status in CITES Species Database II
Researcher(s)  
Reference(s)
RALF KIEFNER, WHALES & DOLPHINS CETACEAN WORLD GUIDE, PUBLISHED BY IKAN, Page: 256
Other Link(s)
Collection Record