Stenella clymene (Gray,
English: Clymene dolphin
Spanish: Delfín clymene
French: Dauphin de Clymène
Stenella clymene ©Würtz-Artescienza
The Clymene dolphin is small but rather stocky and has a moderately
long beak. The dorsal fin is tall and nearly triangular to slightly
falcate, and flippers and flukes resemble those of other members
of the genera Delphinus or Stenella. The coloration
is tripartite: the belly is white, the flanks are light grey and
the cape is dark grey. There is a dark grey line running down the
length of the top of the beak, but the most distinctive feature
is a black "moustache" marking of variable extent at the
top of the beak. With this exception, most of this species' external
characters are very similar to those of the spinner dolphin. Body
size reaches 170-190 cm in females and 176-197 cm in males, and
maximum body mass recorded was 80kg (Jefferson, 2009).
The Clymene dolphin is found in tropical and warm temperate waters
of both the North and South Atlantic Oceans. The northernmost records
are from New Jersey (39°17'N) in the western Atlantic and from
Mauritania (16° 13'W) in the eastern Atlantic. The southernmost
record on the west is from southern Brazil (29°58'S), in the
central Atlantic at 3°40'S off Ascension Island (Fertl et al.
2003), and in the east near northern Angola (7°S, Weir, 2006).
It can be expected to occur along the eastern seaboard of the United
States, throughout the Gulf of Mexico and Caribbean, along the north-eastern
coast of South America, throughout the equatorial Atlantic and along
the entire tropical coast of West Africa (Perrin and Mead, 1994).
Distribution of Stenella clymene (Hammond
et al. 2008; © IUCN; enlarge
the species prefers the tropical, subtropical and occasionally the
temperate waters of the Atlantic Ocean
3. Population size
The scarcity of records of this species indicates that the Clymene
dolphin may not be very abundant, at least in coastal waters. Considering
the difficulty of distinguishing it from similarly marked species
at sea, however, it may not be as rare as it would seem to be (Perrin
and Mead, 1994). The best recent abundance estimate for the western
North Atlantic is 6,086 animals (CV = 0.93) (Mullin and Fulling
2003). No Clymene dolphins have been
observed in subsequent surveys (Waring et al. 2007). The best available
abundance estimate for the northern Gulf of Mexico in oceanic waters,
pooled from 2003 to 2004, was 6,575 (CV=0.36) (Mullin 2007).
Based on capture records, S. clymene appears to be the most
common cetacean in Ghana's coastal waters, but no individual stocks
have been distinguished on the coasts of West Africa (Van Waerebeek
et al. 2000 and refs. therein). However, new West African specimens
of S. clymene are evidence that the present unequal distribution
of this species in the western and eastern parts of the tropical
North Atlantic could be an artefact of poor sampling in African
waters (Robineau et al. 1994).
4. Biology and Behaviour
Habitat: Clymene dolphins were found in waters
with bottom depths ranging from 44 to 4500 m (mean = 1870 m). A
single sighting reported at a location with a bottom depth of 44
m is considered to be atypical, as this species has an otherwise
exclusively oceanic distribution (Perrin and Mead, 1994, and refs.
therein; Fertl et al. 2003).
Schooling: Group sizes range from at least one individual
in a mixed-species school of spinner dolphins S.
longirostris to a group of an estimated 1000 animals (mean
= 71). Stranding group size range from 1 to 46 individuals, with
single individuals being most common . There is information available
for seven mass strandings, all of which occurred in the south-eastern
USA (Fertl et al. 2003)
Watkins and Moore (1982, in Perrin and Mead, 1994) observed groups
of 1-10 animals around St Vincent in the Caribbean. The Clymene
dolphins were swimming in close association with schools of spinner
dolphins but remained clustered together and did not approach the
vessel as closely as the spinners did. Three groups of Clymene dolphins
seen off the US coast consisted of three, eight and 15 animals.
Perrin and Mead (1994) also reported that schools of this species
may be segregated by sex and age; three mass strandings in Florida
were of two females with calves, three adult males, and six adult
males. Of 47 specimens from a mass stranding in Louisiana in 1985,
43 were males (164-197cm), two were females (155 and 168cm, probably
immature) and two were of unknown sex.
A school off West Africa consisted of approximately 50 dolphins.
Schools of this species have also been seen in the company of common
delphis) off West Africa (Perrin and Mead, 1994, and refs.
Photo: Carol Roden /NMFS
Food: Clymene dolphins may be night feeders on small fish
and squids. The stomach of one stranded specimen contained one pair
of small squid beaks (unidentified) and over 800 very small otoliths
of fishes of the families Myctophidae, Argentinidae and Bregmacerotidae.
Most of the species represented are mesopelagic but known to reach
the surface at night during the course of vertical migrations. One
myctophid (Lampanyctus sp.) usually does not occur in surface
waters even at night (Perrin and Mead, 1994, and refs. therein).
As opposed to this, Fertl et al. (1997) report on Clymene dolphins
feeding during the daytime in a co-ordinated manner on schooling
fish in the Gulf of Mexico in water 1,243m deep.
Direct catches: Clymene dolphins were taken by harpoon in
small numbers in a subsistence fishery at St Vincent in the Lesser
Antilles (Perrin and Mead, 1994 and refs. therein). Off the coast
of West Africa, this species is possibly one of several taken in
large numbers in tuna purse seines in the Gulf of Guinea (Van Waerebeek
et al. 2000).
Incidental catch: They were captured incidentally in gillnets
in Venezuelan waters and utilised for longline shark bait and for
human consumption (Perrin and Mead, 1994 and refs. therein). They
may be one of the species taken in tuna purse seines in the eastern
tropical Atlantic (Jefferson et al. 1993) and have been recorded
from by-catches in Brazilian fisheries (Zerbini and Kotas, 1998).
Annual estimated fishery-related mortality and serious injury to
the US western Atlantic and the northern Gulf of Mexico stocks during
2001-2005 were zero, as there were no reports of deaths or serious
injury to Clymene dolphins (Waring et al. 2007).
Pollution: Contaminant levels have not been recorded (Jefferson
and Curry, 2003).
Range states (Hammond et al. 2008)
Antigua and Barbuda; Bahamas; Barbados; Belize; Brazil; Cameroon;
Cape Verde; Cayman Islands; Côte d'Ivoire; Dominica; Gabon;
Ghana; Guinea; Honduras; Jamaica; Mauritania; Mexico; Netherlands
Antilles; Puerto Rico; Saint Helena; Saint Vincent and the Grenadines;
Senegal; Sierra Leone; USA; Venezuela.
The Clymene dolphin is listed as "Data Deficient" by
the IUCN. The West African population is listed in Appendix II of
CMS. The species is listed in Appendix II of CITES.
The species is poorly known with respect to biology, life history,
distribution and migratory habits. Further research on all aspects
of its biology is needed. Sightings at sea suggest a wide home-range,
and individuals or groups thus may cross many international boundaries,
especially in the Caribbean. Therefore, full inclusion in Appendix
II of CMS should be considered.
See further recommendations in Hucke-Gaete (2000) in Appendix
· Fertl D, Schiro AJ, Peake D (1997) Coordinated
feeding by Clymene dolphins (Stenella clymene) in the Gulf
of Mexico. Aquat Mamm 111-112.
· Fertl D, Jefferson TA, Moreno IB, Zerbini AN, Mullin KD
(2003) Distribution of the Clymene dolphin Stenella clymene.
Mammal Rev 33: 253-271.
· Jefferson TA, Leatherwood S, Webber MA (1993) FAO Species
identification guide. Marine mammals of the world. UNEP/FAO, Rome,
· Jefferson TA (2009) Clymene dolphin - Stenella clymene.
In: Encyclopedia of marine mammals, 2nd Ed. (Perrin WF, Würsig
B, Thewissen JGM, eds.) Academic Press, Amsterdam, pp. 241-243.
· Jefferson TA, Curry BE (2003) Stenella clymene.
Mamm Spec. 726: 1-5
· Hammond PS, Bearzi G, Bjørge A, Forney K, Karczmarski
L, Kasuya T, Perrin WF, Scott MD, Wang JY, Wells RS, Wilson B (2008)
Stenella clymene. In: IUCN 2009. IUCN Red List of Threatened
Species. Version 2009.2. <www.iucnredlist.org>.
· Hucke-Gaete R ed. (2000) Review on the conservation status
of small cetaceans in southern South America. UNEP/CMS Secretariat,
Bonn, Germany, 24 pp.
· Mullin, K. D. 2007. Abundance of cetaceans in the oceanic
Gulf of Mexico based on 2003-2004 ship surveys. 26 pp. Available
from: NMFS, Southeast Fisheries Science Center, P.O. Drawer 1207,
Pascagoula, MS 39568
· Mullin KD, Fulling GL (2003) Abundance of cetaceans in
the southern U.S. North Atlantic Ocean during summer 1998. Fish
Bull 101: 603-613
· Perrin WF, Mead JG (1994) Clymene dolphin - Stenella
clymene. In: Handbook of marine mammals (Ridgway SH, Harrison
SR, eds.) Vol. 5: The first book of dolphins. Academic Press, London,
· Robineau D, Vely M, Maigret J (1994) Stenella clymene
(Cetacea, Delphinidae) from the coast of West Africa. J Mamm 75:
· Van Waerebeek K, Ndiaye E, Djiba A, Diallo M, Murphy P,
Jallow A, Camara A, Ndiaye P, Tous P (2000) A survey of the conservation
status of cetaceans in Senegal, the Gambia and Guinea-Bissau. UNEP/CMS
Secreta-riat, Bonn, Germany, 80 pp.
· Waring GT, Josephson E, Fairfield-Walsh CP, Maze-Foley
K, editors (2007) U.S. Atlantic and Gulf of Mexico marine mammal
stock assessments -- 2007. NOAA Tech Memo NMFS NE 205; 415 p.
· Weir CR (2006) Occurrence and distribution of cetaceans
off northern Angola, 2004/05. J Cetacean Res Manage 9: 225-239
· Zerbini AN, Kotas JE (1998) A note on cetacean bycatch
in pelagic driftnetting off southern Brazil. Rep Int Whal Comm 48:
© Boris Culik (2010) Odontocetes.
The toothed whales: "Stenella clymene". UNEP/CMS
Secretariat, Bonn, Germany.http://www.cms.int/small-cetaceans
© Illustrations by Maurizio Würtz, Artescienza.
© Maps by IUCN.