Clymene dolphin

Stenella clymene
Other names: 
  • Helmet dolphin
  • Senegal dolphin
  • Short-snouted spinner dolphin
  • Atlantic spinner dolphin
Maximum length: 
  • Male: 2m
  • Female: 1.9m
  • Calf: 1.2m
Maximum weight: 
  • Male: 80 kg's
  • Female: Unknown
  • Calf: 10 kg's
  • Fish (myctophids)
  • Squid
Estimated population: 
IUCN Listing: 
CITES Appendix: 
CMS Appendix: 
II (West African population)

The Clymene dolphin was only recently classified as a separate species. Until 1981 it was thought to be a variant of the spinner dolphin, but examination of skulls showed differences that required separate classification for the species. In the wild the two species may be easily confused; observation of behaviour and distinctive facial markings allows for accurate identification.


As might be expected, the Clymene dolphin shares many characteristics with the spinner dolphin. However, it is more robust and its beak, while distinct, is slightly shorter than that of its close relative. The dorsal fin is triangular to slightly falcate and the flippers are slender and sharply pointed. The flukes have concave trailing edges with pointed tips and a distinct notch in the middle. The Clymene dolphin has a distinctive tri-colour pattern featuring a dark grey cape which dips down to create an S shape. It has pale grey sides, and the chin and belly are white, sometimes with a pinkish tinge. The medium-length beak has a black tip and ‘lips', and a black stripe along the top. Additional stripes and markings on the face can give the Clymene dolphin a moustached look. There is also a dark grey eye-flipper stripe.


Clymene dolphins are the only species besides spinner dolphins that leap out of the water and spin on the longitudinal axis, though it performs fewer rotations. It breaches and bow rides, occasionally approaching boats. It is thought to feed on small fish including lantern fish and squid. When it is feeding it often associates with other small dolphins such as the common and spinner dolphins. It is generally found in groups of fewer than 50, preferring deep waters and is not generally seen close to shore.


The Clymene dolphin is found only in the tropical and subtropical Atlantic Ocean. This species has a notable warm-water preference, although there are records as far north as New Jersey on the U.S. east coast and as far south as southern Brazil. Their range on the West African coast is not well known, but extends from at least the equator north to Mauritania. Threats to the Clymene dolphin include intentional takes – they are known to be targeted in harpoon fisheries in the Caribbean and off the coast of West Africa, and incidental entanglement in fishing gear. Abundance has only been estimated for a small part of its range and a worldwide population is unknown. The IUCN has categorised this species as Least Concern (2018).

Distribution map: