Risso's Dolphin (species: Grampus griseus) in Lizard Island area: all known taxa (Lizard Island Field Guide)
Grampus griseus
Risso's Dolphin


©Robert Pittmann

©NOAA NMFS SWFSC PRD

©NOAA NMFS SWFSC PRD
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Cetacea
Family Delphinidae
Genus Grampus
Species Grampus griseus
Status least concern

Colours

    

Distinguishing features

A large dolphin with a blunt bulbous head, no beak and a slender tail stem. The dorsal fin is tall with a wide base and slightly concave back edge, positioned about halfway along the body. Colour generally grey with many paler "scribble" marks, apparently scars. Small individuals are darker than larger ones.

Size

  • Up to 400 cm (Length of specimen) - applies to Adults

Depth range

  • Depth range data is not yet available.

Synonyms

Distribution


©Atlas of Living Australia: Australian distribution

Local abundance

  • Lizard Island area: This appears to be the first record of this species from the northern Great Barrier Reef.

Behaviour

The single record reported here is based on about 40 individuals seen at a distance of about 1 km. The pod was swimming slowly along the tide line of a strong outgoing tide, in deep water about 1 nautical mile off the seaward side of Jewell Reef. It included individuals ranging from about 1.5 to about 4 m length. Many individuals performed head stands, poking their tails vertically out of the water, remaining in that position for several seconds.

Web resources

References

  • Baker, A.N. (1983). Whales and Dolphins of New Zealand and Australia: An identification guide Victoria University Press, Wellington, NZ.