The Clymene dolphin is endemic to the Atlantic Ocean. Its full range is still poorly understood, particularly at its southern end.
The Clymene dolphin (Stenella clymene), in older texts known as the short-snouted spinner dolphin, is a dolphinendemic to the Atlantic Ocean. It is the only confirmed case of hybrid speciation in marine mammals, descending from the spinner dolphin and the striped dolphin.
The Clymene dolphin looks very similar to the spinner dolphin. At close quarters, it is possible to observe that the beak of the Clymene is slightly shorter than that of its relative. The dorsal fin is also less erect and triangular.
The basic color of the Clymene dolphin is "cetacean neapolitan" - it occurs in three shaded layers — the underside being white. Next, a strip of light grey runs from just above the beak, round either side of the eye back to the tail stock, where the band thickens. The top layer, from the forehead, along the back to the dorsal fin, and down to the top of the tail stock, is a dark grey. The beak, lips, and flippers are also dark grey in color.
Clymene dolphins grow to about 2 m (6.6 ft) in length and 75 to 80 kg (165 to 176 lb) in weight.
They feed on squid and small schooling fish, hunting either at night, or in mesopelagic waters where there is only limited light.
No figures are available for the size of animals at birth. Gestation, lactation, and maturation periods are all unknown, but are unlikely to vary greatly from others in the Stenella genus. Their longevity is also unknown, although at least one sixteen-year old individual has been reported from a stranding.
Clymenes are fairly active dolphins. Group sizes vary from just four up to around 150 individuals, although about forty is typical. Many of these groups appear to be single-sex, and also to be segregated by the approximate age of the individuals. Clymene dolphins are also highly vocal, making short whistles in a range of 6–19 kHz.