Humpback dolphin
| Humpback dolphin | |
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| Several humpback dolphins surfacing for the air | |
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| Size comparison against an average human | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Cetacea |
| Family: | Delphinidae |
| Genus: | Sousa |
| Species | |
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| Pacific humpback dolphin (Chinese white dolphin) range | |
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| Indian humpback dolphin range | |
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| Atlantic humpback dolphin range | |
Humpback dolphins are members of the genus Sousa. These dolphins are characterized by the conspicuous humps and elongated dorsal fins found on the backs of adults of the species. They are found close to shore along the coast of West Africa (Atlantic species/variety) and right along the coast of the Indian Ocean from South Africa to Australia (Indo-Pacific species/varieties).
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Description [edit]
The humpback dolphin is a coastal dolphin that can be found along the coast of Africa and India down to Australia, areas differing for separate varieties. The humpback dolphin has a hump ahead of the dorsal fin, as well as a careen on a ventral side. The dorsal fin of the humpback dolphin is to some degree falcate. The pectoral fins are considerably small and the tail flukes have a well-defined median notch. On each side of the jaw there are 30 to 34 small coned-shaped teeth. Newborn calves are a cream or pearl shade of white, much like that of an adult beluga whale, whereas the adults have a more dull off-white coloring from the tail to the snout. Their flanks are somewhat of a dark grey, and their stomachs are a lighter shade of grey. Adults can reach from 1.8 to 2.6 metres (5 ft 10 in to 8 ft 6 in) and weigh in the range of 100 to 139 kilograms (220 to 310 lb).[1]
Diet [edit]
The humpback dolphin's main diet consists of mullet and other fish, though the feeding habits are widely unknown, as this animal is not widely known itself.
Taxonomy [edit]
The taxonomy of the Sousa genus is complicated and disputed. As many as five species have been proposed:
- S. chinensis (Chinese white dolphin, Pacific humpback dolphin or Indo-Pacific humpback dolphin)
- S. plumbea (Indian humpback dolphin or Plumbeous humpback dolphin)
- S. teuszi (Atlantic humpback dolphin)
- S. lentiginosa
- S. borneensis
By the mid-2000s, most authorities[2][3][4] accepted just two species—the Atlantic and the Indo-Pacific. However, in his widely used systematic account,[5] Rice identified three species, viewing the Indo-Pacific as two species named simply the Indian and Pacific. The dividing line between the two (sub)species is taken to be Sumatra, one of the Indonesian islands; however, intermixing is thought to be inevitable.
Further, Australian cetologist Graham Ross writes "However, recent morphological studies, somewhat supported equivocally by genetic analyses, indicate that there is a single, variable species for which the name S. chinensis has priority".[6]
Humpback dolphins found in Chinese waters are locally known as Chinese white dolphins. See that article for specific issues relating to that subspecies which corresponds to the Pacific humpback dolphin in Rice's classification.
Conservation [edit]
The species is listed on Appendix I[7] and Appendix II[7] of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix I[7] as this species has been categorized as being in danger of extinction throughout all or a significant proportion of its range and CMS Parties strive towards strictly protecting these animals, conserving or restoring the places where they live, mitigating obstacles to migration and controlling other factors that might endanger them. It is listed on Appendix II[7] as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements. [8]
In addition, the Atlantic humpback 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).[9]
See also [edit]
References [edit]
- ^ "Atlantic Humpback". ThinkQuest. Retrieved January 2013.
- ^ National Audubon Society Guide to Marine Mammals of the World (2002) ISBN 0-375-41141-0
- ^ Cetacean Societies: Field Studies of Whales and Dolphins Mann, Connor, Tyack and Whitehead (2000) ISBN 0-226-50340-2
- ^ Whales, Dolphins and Porpoises Mark Carwardine (1995) ISBN 0-7513-2781-6
- ^ Land Mammals of the World. Systematics and Distribution, Dale W. Rice (2000). Published by the Society of Marine Mammalogy as Special Publication No. 4
- ^ Humpback Dolphins Graham J. B. Ross pps 585-589 in Encyclopedia of Marine Mammals (1998) ISBN 0-12-551340-2
- ^ a b c d "Appendix I and 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.
- ^ Convention on Migratory Species page on the Atlantic humpback dolphin
- ^ Memorandum of Understanding Concerning the Conservation of the Manatee and Small Cetaceans of Western Africa and Macaronesia
