Clymene dolphin

Clymene dolphin[1]
Clymene dolphins
Size compared to an average human
Conservation status
Data Deficient (IUCN 3.1)[2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Cetacea
Family:	Delphinidae
Genus:	Stenella
Species:	S. clymene
Binomial name
Stenella clymene Gray, 1846
Clymene Dolphin range

The Clymene dolphin (Stenella clymene), in older texts known as the Short-snouted spinner dolphin, is a dolphin endemic to the Atlantic Ocean.

Taxonomy

From its description by John Gray in 1850 until a re-assessment in 1981, the Clymene dolphin was regarded as subspecies of the Spinner dolphin. In 1981, Perrin et al. asserted the Clymene's existence as separate species. Up until this time, because Clymenes are relatively remote and regarded as "the same" as more accessible Spinners they were never heavily studied. Mead and Perrin went some way to redress this balance but the Clymene dolphin is still one of the least understood of all cetaceans.

Physical description

The Clymene dolphin looks very similar to the Spinner dolphin and at sea, where the two species may intermingle in large groups, they may be indistinguishable. At close quarters it is possible to observe that the beak of the Clymene is slightly shorter that its relative. The dorsal fin is also less erect and triangular.

The basic color of the Clymene dolphin is "cetacean neapolitan" - it comes in three shaded layers - the underside being a white-pink color. Next comes a strip of light grey that runs from just above the beak, round either side of the eye all the way 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 metres (6 ft 7 in) in length and 75–80 kg in weight. No figures are available for the size of animals at birth. Gestation, lactation, maturation and longevity periods are all unknown but are unlikely to vary greatly from others in the Stenella genus.

Clymenes are fairly active dolphins. They do spin longitudinally when jumping clear of the water, but not with as much regularity and complexity as the Spinner dolphin. They will also approach boats and bow-ride. Diet is likely to consist of small fish and squid. Group sizes vary from just a few individuals to great schools numbering up to 500.

Population and distribution

The Clymene dolphin is endemic to the Atlantic Ocean. Its full range is still poorly understood, particularly at its southern end. The species certainly prefers temperate and tropical waters. The northern end of the range runs approximately from New Jersey east-south-east to southern Morocco. The southern tips runs from somewhere around Angola to Rio de Janeiro. They appear to prefer deep water. Plenty of sightings have been recorded in the Gulf of Mexico. The species has not been sighted however in the Mediterranean Sea.

Total population is unknown. The only population estimate available is for the north part of the Gulf of Mexico, where a count of 5,500 individuals was reported. The species may be naturally rare in comparison with others in the Stenella genus.

Human interaction

Some individuals have been killed from directed fisheries in the Caribbean and others in nets off West Africa.

Conservation

The West African population of the Clymene dolphin is listed on Appendix II^[3] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS), since it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.

The Clymene dolphin is covered by the Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia (Western African Aquatic Mammals MoU).

References

1. ^ Mead, James G.; Brownell, Robert L., Jr. (16 November 2005). "Order Cetacea (pp. 723-743)". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=14300088. 
2. ^ HammondHammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. (2008). Stenella clymene. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 7 October 2008.
3. ^ "Appendix II" of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). As amended by the Conference of the Parties in 1985, 1988, 1991, 1994, 1997, 1999, 2002, 2005 and 2008. Effective: 5th March 2009.

Bibliography

• Carwardine, Mark. Whales Dolphins and Porpoises, Dorling Kindersley Handbooks, ISBN 0-7513-2781-6.
• Dee, Eileen Mary and Mark McGinley. 2010. Clymene dolphin. Encyclopedia of Earth. topic ed. C. Michael Hogan. ed. Cutler J. Cleveland, NCSE, Washington DC
• Jefferson, Thomas A. "Clymene Dolphin" in Encyclopedia of Marine Mammals, 234–236. ISBN 0-12-551340-2
• Jefferson, Thomas A.; and Barbara E. Curry. (2003). "Stenella clymene". Mammalian Species 726 (726): 1–5. doi:10.1644/726. http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/default.html. 
• Perrin and Mead. (1994). "Clymene Dolphin" in Handbook of Marine Mammals. 5: 161–171.
• Perrin, Mitchell, Mead, Caldwell and van Bree. (1981) Stenella clymene, a rediscovered tropical dolphin of the Atlantic, Journal of Mammalogy. 62: 583–589.
• Reeves, Stewart, Clapham and Powell. National Audubon Society Guide to Marine Mammals of the World, ISBN 0-375-41141-0.

External links

• The National Oceanic and Atmospheric Administration (NOAA)
• Convention on Migratory Species page on the Clymene dolphin
• Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia