Humpback dolphin
Encyclopedia
Humpback dolphins are members of the genus
Sousa. These dolphin
s are characterized by the conspicuous humps and elongated dorsal fin
s found on the back of adult members 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).
, 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 meters to 2.4 meters (6'6" to 8'2") and weigh in the range of 100 kg to 139 kilograms (220 pounds to 306 pounds).
and other fish, though the feeding habits are widely unknown, as this animal is not widely known itself.
By the mid-2000s most authorities accepted just two species—the Atlantic and the Indo-Pacific. However, in his widely used systematic account, 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 Indonesia
n islands; however, intermixing is thought to be inevitable.
Further, Australia
n 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".
Humpback dolphins found in Chinese
waters are locally known as Chinese white dolphin
s. See that article for specific issues relating to that subspecies which corresponds to the Pacific humpback dolphin in Rice's classification.
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).
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Sousa. These dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s are characterized by the conspicuous humps and elongated dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s found on the back of adult members of the species. They are found close to shore along the coast
Coast
A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...
of West Africa
West Africa
West Africa or Western Africa is the westernmost region of the African continent. Geopolitically, the UN definition of Western Africa includes the following 16 countries and an area of approximately 5 million square km:-Flags of West Africa:...
(Atlantic species/variety) and right along the coast of the Indian Ocean
Indian Ocean
The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded on the north by the Indian Subcontinent and Arabian Peninsula ; on the west by eastern Africa; on the east by Indochina, the Sunda Islands, and...
from South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
to Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
(Indo-Pacific species/varieties).
Description
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 finDorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
, 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 meters to 2.4 meters (6'6" to 8'2") and weigh in the range of 100 kg to 139 kilograms (220 pounds to 306 pounds).
Diet
The Humpback Dolphin's main diet consists of mulletMullet
- Fish :* Mullet , or "grey mullets", of the family Mugilidae, of which the most widely known species is the striped mullet, Mugil cephalus* Goatfish, or "red mullets", of the family Mullidae; in particular, red mullets of the genus Mullus...
and other fish, though the feeding habits are widely unknown, as this animal is not widely known itself.
Taxonomy
The taxonomy of the Sousa genus is complicated and disputed. As many as five species have been proposed:- S. chinensis (Chinese white dolphinChinese White DolphinThe Chinese white dolphin is a humpback dolphin species, one of eighty cetacean species. An adult is white or pink and may appear as an albino dolphin to some. Uniquely, the population along the Chinese coast has pink skin. Pink skin is not pigment, but blood vessels for thermoregulation...
or Pacific humpback dolphin or Indo-Pacific humpback dolphin) - S. plumbea (Indian humpback dolphin, Plumbeous humpback dolphin)
- S. teuszi (Atlantic humpback dolphin)
- S. lentiginosa
- S. borneensis
By the mid-2000s most authorities accepted just two species—the Atlantic and the Indo-Pacific. However, in his widely used systematic account, 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
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, one of the Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
n islands; however, intermixing is thought to be inevitable.
Further, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n cetologist
Cetology
Cetology is the branch of marine mammal science that studies the approximately eighty species of whales, dolphins, and porpoise in the scientific order Cetacea...
Graham Ross writes "However, recent morphological studies, somewhat supported equivocally by genetic analyses
Molecular phylogeny
Molecular phylogenetics is the analysis of hereditary molecular differences, mainly in DNA sequences, to gain information on an organism's evolutionary relationships. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree...
, indicate that there is a single, variable species for which the name S. chinensis has priority".
Humpback dolphins found in Chinese
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
waters are locally known as Chinese white dolphin
Chinese White Dolphin
The Chinese white dolphin is a humpback dolphin species, one of eighty cetacean species. An adult is white or pink and may appear as an albino dolphin to some. Uniquely, the population along the Chinese coast has pink skin. Pink skin is not pigment, but blood vessels for thermoregulation...
s. See that article for specific issues relating to that subspecies which corresponds to the Pacific humpback dolphin in Rice's classification.
Conservation
The species is listed on Appendix I and Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). It is listed on Appendix I as this species has been categorized as being in danger of extinction throughout all or a significant proportion of their 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 as it has an unfavourable conservation status or would benefit significantly from international co-operation organised by tailored agreements.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).