The Clymene dolphin is externally similar to the spinner dolphin, but is smaller and more robust, with a much shorter and stockier beak. The dorsal fin is falcate, as opposed to the more triangular fins of spinners. Despite the general similarities with the spinner dolphin, skull morphology indicates that the Clymene dolphin may be more closely related to the striped dolphin.
A three-part color pattern, with a dark gray cape, light gray sides, and white belly, is characteristic of this species. The cape dips in two places, above the eye and below the dorsal fin. The beak is mostly light gray, but the lips and beak tip are black. There is also a dark stripe on the top of the beak, from the tip to the apex of the melon, and often a dark "moustache" marking on the middle of the top of the beak. The eye is also surrounded by black, and a dark gray stripe runs from the eye to the flipper. Tooth counts are much lower than in spinners 39-52 teeth per row. They are slender and pointed.
Clymene dolphins are known to reach at least 1.97 m (males) and 1.90 m (females) in length, and sexual maturity is reached by about 1.7-1.8 m. Newborn length is unknown, but is less than 1.2 m. This species reaches weights of at least 80 kg.
Can be Confused With
Clymene dolphins are most easily confused with spinner dolphins, but are more robust, with shorter, stubbier beaks. Also, the color pattern is slightly different; the two dips in the cape and the dark "moustache" marking on top of the beak will allow Clymene dolphins to be distinguished. The body shape of Clymene dolphins also closely resembles that of the short-beaked common dolphin, as does the color pattern in a superficial way. Common dolphins can best be distinguished by their hourglass pattern, cape that forms a "V" below the dorsal fin, chin-to-flipper stripe, and absence of a "moustache."
The Clymene dolphin is found only in the tropical and subtropical Atlantic Ocean, including the Caribbean Sea and Gulf of Mexico. This species has a notable warm-water preference, although there are records as far north as New Jersey on the United States east coast and as far south as southern Brazil. The limits on the West African coast are not well known, but extend from at least the equator north to Mauritania. This is a deep water, oceanic species, not often seen near shore.
Ecology and Behavior
The Clymene dolphin’s habitat includes oceanic waters. Very little is known of the Clymene dolphin’s natural history. This partly due to the long-standing confusion between this and other similar long-beaked tropical delphinids, as well as the species’ offshore habitat. Schools tend to be smaller than those of spinner dolphins, generally less than 200 animals. They have been reported to associate with common dolphins off West Africa, and spinner dolphins in the Caribbean. These quick and agile dolphins ride bow waves and are aerially active. They have been reported to spin up to 3-4 revolutions on the long axis when breaching. Almost nothing is known of the life history of this species.
Feeding and Prey
Very few stomachs have been examined, and even fewer observations of feeding behavior reported in the literature. Clymene dolphins apparently feed on small fish and squid at moderate depths, presumably mainly at night.
Threats and Status
Main threats include:
• Fisheries bycatch
The IUCN lists the Clymene dolphin as “data deficient”. The United States does not list this species as threatened or endangered. Although they are known to be taken occasionally in dolphin fisheries in the Caribbean, and incidental captures in fishing nets do occur throughout much of the range, the Clymene dolphin is not known to suffer any heavy exploitation at this point. The only exception may be off the coast of West Africa, where this species may be one of several taken in large numbers in tuna purse seines. Using data from 1991 to 1994, the United States National Marine Fisheries Service estimated the northern Gulf of Mexico stock to be 5,571 (CV = 0.37).
Jefferson, T.A. 1996. Morphology of the Clymene dolphin (Stenella clymene) in the northern Gulf of Mexico. Aquatic Mammals 22:35-43.
Jefferson, T.A. 2002. Clymene dolphin Stenella clymene. pp. 234-236 in W.F. Perrin, B. Würsig and J.G.M. Thewissen, eds. Encyclopedia of marine mammals. Academic Press.
Jefferson, T.A. and B.E. Curry. 2003. Stenella clymene. Mammalian Species 726:1-5.
Perrin, W.F., E.D. Mitchell, J.G. Mead, D.K. Caldwell and P.J.H. Van Bree. 1981. Stenella clymene, a rediscovered tropical dolphin of the Atlantic. Journal of Mammalogy 62:583-598.
Perrin, W.F. and J.G. Mead. 1994. Clymene dolphin Stenella clymene (Gray, 1846). pp. 161-171 in S.H. Ridgway and R. Harrison, eds. Handbook of marine mammals, Volume 5: The first book of dolphins. Academic Press.