Heaviside's Dolphin (Cephalorhynchus heavisidii) is a small dolphin that is found off the coast of Namibia and the west coast of South Africa. It is one of four dolphins in the Cephalorhychus genus - the others being the Chilean Dolphin, Hector's Dolphin and Commerson's Dolphin. The conservation status of a species is an indicator of the likelihood of that species continuing to survive. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Phyla Porifera (sponges) Ctenophora (comb jellies) Cnidaria Placozoa Subregnum Bilateria  Acoelomorpha  Orthonectida  Rhombozoa  Myxozoa  Superphylum Deuterostomia     Chordata (vertebrates, etc. ... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... Orders Subclass Embrithopoda (extinct) Subclass Creodonta (extinct) Hyaenodontidae Oxyaenidae Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Placentalia Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Dermoptera Desmostylia (extinct) Hyracoidea Insectivora Lagomorpha Macroscelidea Perissodactyla Pholidota Primates Proboscidea Rodentia Scandentia Sirenia Tubulidentata Xenarthra Subclass Marsupialia Dasyuromorphia Didelphimorphia Diprotodontia Microbiotheria Notoryctemorphia... Eutheria is a taxon (specifically, an infraclass) nearly synonymous with Placentalia, containing the placental mammals and the nearest ancestors of placental mammals (which are known only from the fossil record). ... Suborders Mysticeti Odontoceti (see text for families) The order Cetacea includes whales, dolphins and porpoises. ... Families See text The toothed whales (systematic name Odontoceti) form a suborder of the cetaceans. ... Species Cephalorhyncus commersonii Cephalorhyncus eutropia Cephalorhyncus heavisidii Cephalorhyncus hectori Cephalorhynchus is a genus in the Delphinidae (dolphin) family. ... In biology, binomial nomenclature is a standard convention used for naming species. ... John Edward Gray (February 12, 1800 - March 7, 1875) was a British zoologist. ... Image File history File links Cetacea_range_map_Heavisides_Dolphin. ... Genera See article below. ... Binomial name Cephalorhynchus eutropia Gray, 1846 Chilean Dolphin range The Chilean Dolphin (Cephalorhynchus eutropia), also known as the Black Dolphin (although this name has fallen out of favour in scientific circles), is one of four dolphins in the Cephalorhynchus genus. ... Binomial name Cephalorhynchus hectori Hectors Dolphin range Hectors Dolphin (Cephalorhynchus hectori) is the most well-known of the four dolphins in the genus Cephalorhynchus. ... Binomial name Cephalorhynchus commersonii Lacépède, 1804 Commersons Dolphin range Commersons Dolphin (Cephalorhynchus commersonii) is one of four dolphins in the Cephalorhynchus genus. ...

Name

Heaviside's Dolphin is actually named after a Captain Haviside who brought a specimen from Namibia to the United Kingdom early in the 19th Century. However its name was once mis-spelled Heaviside, after a prominent surgeon, Captain Heaviside who collected cetacean and other animal species. The latter name stuck and is the most common in the popular literature. However some authorities, including the Encyclopedia of Marine Mammals use the originally intended name - Haviside's Dolphin

Population and distribution

Although sightings of the species are not uncommon off the Skeleton Coast of Namibia, Heaviside's Dolphins have not been systematically studied by scientists. They have been recorded off the coast of northern Namibia at 17&deg S and as far south as the southern tip of South Africa. Sightings are often recorded from major population centres such as Cape Town and towns such as Walvis Bay. No estimates of abundance exist. The Skeleton Coast is located on the west coast of Namibia, where the upwelling of the cold Benguela current gives rise to dense ocean fogs for much of the year. ... City motto: Spes Bona (Latin: Good Hope) Province Western Cape Mayor Nomaindia Mfeketo Area  - % water 1,644 km² 0. ... Walvis Bay, Namibia Walvis Bay, (Afrikaans: Walvisbaai meaning Whale Bay), is an area in Namibia with a chequered history. ...

Physical description

Heaviside's Dolphin is a fairly small dolphin - growing up to about 180cm in length and weighing up to 75kg. Their size and bluntness of their head leads these dolphins to often be mistaken for porpoises. The head is coloured a dark grey. The front half of the upper side and the flanks are a much lighter grey. The dorsal fin, fluke and back half of the back are again a darker grey colour. The underbelly is white and there are flashes of white on the flanks below the dorsal fin. Genera Neophocaena Phocoena - Harbor porpoises Phocoenoides - Dalls porpoises The porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. ... Dorsal Fin of the Orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises. ... (A) Fluke is another name for trematodes, a kind of flatworm (for example, the Liver Fluke). ...

Males reach sexual maturity at about 7-9 years. Females reach breeding age at the same time. The gestation period is probably 10 months. Mating occurs in Spring and Summer. It is believed that females calf on average once every three years. The maximum known age of a Heaviside's Dolphin is 20 years. This relatively short life span, coupled with the long calving period, causes a naturally low population growth rate. Therefore the species is particularly sensitive to being hunted.

Heaviside's Dolphins are active and social animals. They typical congregate in groups of about 5-10 in number, and sometimes in larger groups. They are able to swim fast. Part of the play and social activity is to jump vertically clear of the water, turn in the air, and fall back into the sea with virtually no splashing or noise.

References

• National Audubon Society: Guide to Marine Mammals of the World Reeves, Stewart, Clapham and Powell, (2002)
• Cephalorhynchus dolphins, Encyclopedia of Marine Mammals, p200-202, Stephen M. Dawson (1998) ISBN 0125513402