"The Clymene dolphin is distinguished from the very similar spinner dolphin by the shortness of its beak and its color pattern. Like spinners, they ""spin,"" leaping high out the water and rotating (not a somersault, but a sideways roll) several times before splashing back into the water. Clymene dolphins feed on deep-water fish and squid, and except for stranded individuals, have only been seen in deep water. Sharks and large toothed whales such as killer whales, pygmy killer whales, and false killer whales probably prey on them. Often the dolphins have small white marks on their skin that are healed shark bites. The species was first mentioned to in scientific literature with the description of a skull in the 19th century. No one was able to describe the Clymene dolphin scientifically until the 1970s, when some of them stranded in Texas and New Jersey."

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Mammal Species of the World

Clymene dolphins have been seen singly, amongst groups of spinner dolphins, and in large groups of around 100 animals (5). These schools may sometimes be divided by age and sex (2), and sometimes are seen in the company of a group of common dolphins (Delphinus delphis) (4). Clymene dolphins appear to feed in midwater during the night, on fishes and squids, and many bear bite marks and scars from cookie-cutter sharks (Isistius brasiliensis) (4). These attractive and acrobatic dolphins have been observed riding the bow waves of boats and spinning out of the water like spinner dolphins, although the spins are not as high or as complex as those of performed by the spinner dolphin (4).

One of the most recently recognised species of dolphin (2) (4), the Clymene dolphin remains among the least known of the Delphinidae (2). In appearance it is very similar to the spinner dolphin (Stenella longirostris), which is largely why it was not recognised until 1981 as a distinct species. It is a small but stocky dolphin, with a beak of medium length and a dorsal fin that is triangular to nearly triangular. Males are larger and heavier than females, but both sexes have a white belly, light grey flanks and a dark grey cape, and a dark grey line runs down the top of the beak (2) (4). The one distinctive feature that separates the Clymene dolphin in appearance from the spinner dolphin is the black marking, somewhat like a moustache, on top of the beak (2).

The Clymene Dolphin is found only in the tropical and subtropical Atlantic Ocean, including the Caribbean Sea and Gulf of Mexico (Jefferson et al. 1995). 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 (Zerbini and Kotas 1998). The limits on the West African coast are not well known, but extend from at least the equator north to Mauritania. The Clymene Dolphin is not known to enter the Mediterranean Sea (Perrin and Mead 1994, Jefferson and Curry 2003, Fertl et al. 2003).

The clymene dolphin, also known as the "short-snouted spinner dolphin," can be found in tropical and subtropical waters of the Atlantic Ocean (eastern North America to West Africa), the Caribbean, and the Gulf of Mexico. In the United States it has been recorded as far north as New Jersey and along the coast lines of Texas and Louisiana. It has also been recorded as far south as southern Brazil.

Biogeographic Regions: atlantic ocean (Native )

New Jersey to Southern Brazil

Central Atlantic Ocean, European waters (ERMS scope), Gulf of Mexico, North West Atlantic

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Tropical and subtropical Atlantic mainly: southeastern U.S. (north to New Jersey), Gulf of Mexico (Mullin et al. 1994), Caribbean Sea, northwestern coast of Africa, and mid-Atlantic (Leatherwood and Reeves 1983).

The Clymene dolphin occurs in the tropical and warm-temperate waters of the Atlantic Ocean, from West Africa to North America, including the Caribbean and Gulf of Mexico (5).

The clymene dolphin is a small dolphin that averages 1.8m in length. It has a short beak, a white belly, light gray sides, and a dark cape that dips in two points above the eye and below the dorsal fin. The facial markings are very distinct, including black eye rings, dark lips and snout tip, and a dark line on top of the snouts sometimes making a "moustache" near the apex of the melon. The cape sometimes has blotchy patches on the sides, and the dorsal fin is gray but bordered with dark margins.

On average members of this species have 38 to 49 teeth on each side of the upper and lower jaws, which are slender and pointed.

Average mass: 85 kg.

Sexual Dimorphism: None

Length:
Range: "1.8-2 m "

Weight:
Range: 45-85 kg

Habitat and Ecology

Systems

• Marine

The clymene dolphin is a deep water species that has only been observed at sea in waters with depths of 250m-5000m or deeper. It is not normally seen near the shore.

Aquatic Biomes: coastal

tropical and subtropical, oceanic

Depth range based on 68 specimens in 1 taxon.
Water temperature and chemistry ranges based on 66 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): 20.220 - 26.266
  Nitrate (umol/L): 0.348 - 1.709
  Salinity (PPS): 33.002 - 35.958
  Oxygen (ml/l): 4.660 - 5.288
  Phosphate (umol/l): 0.142 - 0.342
  Silicate (umol/l): 0.982 - 3.398

Graphical representation

Temperature range (°C): 20.220 - 26.266

Nitrate (umol/L): 0.348 - 1.709

Salinity (PPS): 33.002 - 35.958

Oxygen (ml/l): 4.660 - 5.288

Phosphate (umol/l): 0.142 - 0.342

Silicate (umol/l): 0.982 - 3.398
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Habitat Type: Marine

Comments: Has been observed at sea only in deep water (250-5000+ m) (IUCN 1991).

Clymene dolphins have been generally observed in deep, offshore, tropical and warm-temperate waters, at depths of 44 to 4,500 metres (2) (5).

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: No. No populations of this species make annual migrations of over 200 km.

The clymene dolphin feeds mostly at night when squids and small fish come to the surface of the water.

Animal Foods: fish; mollusks

Primary Diet: carnivore (Piscivore , Molluscivore )

Comments: Apparently a mid-water or night feeder that preys on small fishes and squid (Leatherwood and Reeves 1983).

In the Gulf of Mexico, herd size was 2-100 (mean 42) individuals (Mullin et al. 1992).

No information is currently available on the reproduction of the species. Some information is available for a close relative, the spinner dolphin, Stenella longiristris. Adult females of this species give birth to a single calf at 2 year intervals. Parturition most often occurs in early summer, but can occur in any season. The period of gestation is 11 months and calves are born about 75cm long.

There are no records on how many clymene dolphins have been captured or killed, but clymene dolphins are occasionally taken by harpoon in small numbers in the Lesser Antilles (Caribbean) small cetacean fishery. They are captured in gillnets in Venezuelan waters, where they are used for longline shark bait and human consumption. They may also betaken in tuna purse seines in the eastern tropical Atlantic.

Contaminant levels have not been recorded.

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: data deficient

United States

Rounded National Status Rank: NU - Unrankable

Rounded Global Status Rank: G4 - Apparently Secure

Classified as Data Deficient (DD) on the IUCN Red List (1), and listed on Appendix II of CITES (3).

Population

Population Trend

Major Threats

Comments: No known threats, though incidental take in pelagic driftnet fisheries warrants investigation (IUCN 1991).

While the Clymene dolphin is currently not known to be facing any serious threats, the lack of research on this species means that the problems could simply be undocumented (2). These dolphins are harpooned in the Lesser Antilles and are sometimes caught in fishing gear in other areas (1). Bycatch is likely to occur in many parts of its range, but is thought to be most significant in the eastern tropical Atlantic, off West Africa, where considerable numbers may be taken in tuna purse seines. Clymene dolphins are also captured in this area for food (1) (2).

Conservation Actions

The Clymene dolphin is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in this species should be carefully monitored to ensure its compatibility with the species' survival (3). The lack of information regarding this species current status has led to the IUCN being unable to assess its risk of extinction, and thus it is classified as Data Deficient (1). Further research into this enchanting marine mammal is clearly needed, particularly into the impact of bycatch and intentional hunting in West Africa, so that conservation measures can be promptly implemented if required.

The only possible way that clymene dolphins can have a negative effect on humans is that they eat fish and squid. It is not clear what kind of fish and squid they eat, but if they eat the same types that humans also consume then the fish and squid could become scarce.

The clymene dolphin, when captured in gillnets, is used for shark bait and for human consumption.

Comments: Sometimes taken in the small cetacean fisheries in the Caribbean region, probably for human consumption (IUCN 1991).

Data Deficient (DD)