Sealife guideThe risso's dolphinGrampus griseus

Last updated on 01/19/2026 at 11:38 PM

Taxonomy

Common name: Risso's dolphin
French name: Dauphin de Risso
Scientific name: Grampus griseus (G. Cuvier, 1812)
Family name: Delphinidae
Order name: Cetacea
Class name: Sea mammals [Mammalia]

Description

The Risso's dolphin owes its common name to a naturalist from Nice (France), Giuseppe Antonio Risso (1777–1845), who devoted most of his work to zoology through the study of marine wildlife in the Nice region, although he also conducted research in botany.

The risso's dolphin (Grampus griseus) © Natursports | Dreamstime.com

The Risso's dolphin is a medium-sized dolphin species, measuring approximately 10 to 13 feet in length. Its body, which becomes lighter gray over time, is covered with numerous whitish scars and markings that reflect the many interactions between individuals during conflicts or playful behavior.

Its head lacks a beak and its dorsal fin is centrally positioned, sickle-shaped and particularly tall compared to its body size.

Geographic range

Risso's dolphin is a common dolphin species in the Mediterranean sea, especially in the western basin. It is also found in the temperate waters of the North Atlantic ocean, particularly around the Azores archipelago.

Habitat

Risso's dolphin lives in small groups averaging around ten individuals, with rarely more than 20 dolphins per group. These groups usually inhabit the continental slope zone.

Diet

Risso's dolphin mainly feeds on cephalopods, especially squid, which it can hunt at great depths.

Reproduction

Risso's dolphin breeds during the summer season and a gestation period of 12 to 13 months is required before the calf is born.

Did you know ?

Risso's dolphin is one of the five dolphin species commonly found in the Mediterranean sea, along with the striped dolphin (Stenella coeruleoalba), the common dolphin (Delphinus delphis), the bottlenose dolphin (Tursiops truncatus) and the long-finned pilot whale (Globicephala melas).

The risso's dolphin (Grampus griseus) © Jaime Debrum | Dreamstime.com

The risso's dolphin is listed as many other marine species within The IUCN Red List of threatened species. The risso's dolphin appears in the IUCN Red List since 2018 within the category Least Concern !

Within the same family

Common bottlenose dolphin
(Tursiops truncatus)

False killer whale
(Pseudorca crassidens)

Indo-Pacific humpback dolphin
(Sousa chinensis)

Pacific white-sided dolphin
(Sagmatias obliquidens)

Short-beaked common dolphin
(Delphinus delphis)

Spinner dolphin
(Stenella longirostris)

Striped dolphin
(Stenella coeruleoalba)

White headed dolphin
(Cephalorhynchus hectori)

Discover also

Antarctic fur seal
(Arctocephalus gazella)

Australian sea lion
(Neophoca cinerea)

Beluga
(Delphinapterus leucas)

Dugong
(Dugong dugon)

Harbor seal
(Phoca vitulina)

Humpback whale
(Megaptera novaeangliae)

Narwhal
(Monodon monoceros)

Sperm whale
(Physeter macrocephalus)

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