Atlantic white-sided dolphin

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Atlantic white-sided dolphin
Lagenorhynchus acutus.jpg
Atlantic white-sided dolphin size.svg
Size compared to an average human
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Subclass: Eutheria
Order: Cetacea
Suborder: Odontoceti
Family: Delphinidae
Genus: Lagenorhynchus
Species: L. acutus
Binomial name
Lagenorhynchus acutus
(Gray, 1828)
Cetacea range map Atlantic White-sided Dolphin.PNG
Atlantic white-sided dolphin range

The Atlantic white-sided dolphin (Lagenorhynchus acutus) is a distinctively coloured dolphin found in the cool to temperate waters of the North Atlantic Ocean.

Taxonomy[edit]

The Atlantic white-sided dolphin was named by John Edward Gray in 1828. The specific name acutus comes from the Latin for 'pointed' and refers to the sharply pointed dorsal fin. L. acutus is one of six oceanic dolphins in the genus Lagenorhynchus.

Physical description[edit]

An Atlantic white-sided dolphin off the coast of Cape Ann, Massachusetts

The dolphin is slightly larger than most other oceanic dolphins. It is just over a meter in length at birth, growing to about 2.8 m (9.2 ft) (males) and 2.5 m (8.2 ft) (females) at maturity. It weighs 200–230 kg (440–510 lb) once fully-grown. Females reach sexual maturity at between 6 and 12 years, and males between 7 and 11 years. The gestation period is 11 months and lactation lasts for about a year and a half — both typical figures for dolphins. Individuals are known to live for up to 22 years (males) and 27 years (females).

The key distinguishing feature is the white to pale yellow patch found behind the dorsal fin of the dolphin on each side. This colour variation is unique amongst the mixtures of white, greys and blues of other pelagic cetaceans. The rest of the body's coloration is well demarcated: the chin, throat and belly are white; the flippers, dorsal fin and back are dark grey to black with the exception of the yellow patch; there is a further white patch below the dorsal fin, lying above a light grey stripe that runs from the beak, above the eye and down to the tail stock.

Dolphin group sizes vary by location, with groups averaging 60 in number close to the Newfoundland shores, but rather smaller east of Iceland. From the analysis of the stomach contents of stranded animals, fish such as herring and mackerel and squid appear to form the species' main diet. The Atlantic white-sided dolphin is fairly acrobatic and keen to interact with boats, however it is not as wildly gregarious as the white-beaked and common dolphins.

Population and distribution[edit]

The species is endemic to the North Atlantic Ocean. Areas of particularly high population density include the shores of Newfoundland and Cape Cod, the triangular area of sea between the United Kingdom, Iceland and Greenland and the North Sea. The total population is believed to be 200-300,000 individuals.

Human interaction[edit]

Hvalba, Faroe Islands in August 2006

Historically, Atlantic white-sided dolphins were killed in drives conducted from Norway and Newfoundland. These have ceased in recent years, although they still occur to a lesser extent from the Faroe Islands, where the meat and blubber are in high regard as food.[2]

Reported catches in the years from 1995 to 1998 were 157, 152, 350, and 438, respectively (Bloch and Olsen 1998, 1999; Bloch et al. 1997, 2000). In 2002, the number reported killed was 774. [2]

Conservation[edit]

The North and Baltic Sea populations of the Atlantic white-sided dolphin are listed on Appendix II [3] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). They are listed on Appendix II[3] as they have an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.[4]

In addition, the Atlantic white-sided dolphin is covered by the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS).[5]

See also[edit]

References[edit]

  1. ^ Hammond, 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). Lagenorhynchus acutus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 24 March 2009. Database entry includes a brief justification of why this species is of least concern.
  2. ^ a b UMSITINGEN: 10JUNR2003 report by the Faroe Islands' Prime Minister's Office, entitled: Whales & Whaling in the Faroe Islands
  3. ^ a b "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: 5 March 2009.
  4. ^ Convention on Migratory Species page on the Atlantic white-sided dolphin
  5. ^ Official website of the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas

External links[edit]