Chilean Dolphin Conservation status: Unknown
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Subclass: Eutheria Order: Cetacea Suborder: Odontoceti Genus: Cephalorhynchus Species: C. eutropia
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. The dolphin is only found off the coast of Chile. 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 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 Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals characterized by the presence of mammary glands... Eutheria is a classification system nearly synonymous with Placentalia. ... Suborders Mysticeti Odontoceti (see text) 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 , User:Pcb21 after User:Vardion. ... Genera See article below. ... Species Cephalorhyncus commersonii Cephalorhyncus eutropia Cephalorhyncus heavisidii Cephalorhyncus hectori Cephalorhynchus is a genus in the Delphinidae (dolphin) family. ...

Physical description

The Chilean Dolphin is a small dolphin at around 170 cm in length, with a blunt head. These characteristics often make for incorrect identification as a porpoise. The Dolphin is thickly-shaped with its girth up to two-thirds its length. The dorsal fin and flippers are small in proportion to body size in comparison with other dolphins. The throat, underside and the closest part of the flippers to the body are white. The remainder of the body is a mix of greys. The Dolphin has 28-34 pairs of teeth in the upper jaw and 29-33 in the lower.

The Dolphin is normally sighted in small groups of around two to ten individuals, with some larger gatherings occasionally sighted.

Longevity, gestation and lactation periods are not known, but are believed to be similar in length to the more studied, and similar, Hector's and Commerson's Dolphins which have a gestation period of about ten months to one year and maximum longevity of twenty years. 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. ...

Population and distribution

The population of the Chilean Dolphin, perhaps one of the least studied of all cetaceans, is not known with certainty. There may be as many as a few thousand individuals, although at least one researcher, Steve Leatherwood, has suggested that the population may be much lower (see also [1] for a survey of South American cetacean population with data on the Chilean Dolphin). Whatever its number, the Chilean Dolphin is endemic to the coast of Chile and thought not to migrate. The dolphin is seen over a wider interval of latitudes than other Cephalorhynchus species - from Valparaíso at 33° S to Cape Horn at 55° S. The species appears to prefer areas of shallow water (less than 200 m depth) and in particular enjoys fast-flowing tidal areas and mouths of rivers. Suborders Mysticeti Odontoceti (see text) The order Cetacea includes whales, dolphins and porpoises. ... Valparaíso is one of the main seaports of Chile, on the Pacific Ocean, and the capital of the Valparaíso Region. ... Cape Horn is often said to be the southernmost point of South America. ...

Name

In the early part of the twentieth century the Chilean Dolphin was commonly known as the Black Dolphin. This was later agreed to be a poor choice of name. Most of the few individual specimens studied by scientists were either washed-up individuals whose skin had darkened due to exposure to air or live specimens seen at sea but only at a distance (and so appeared darker than they were). As more specimens were studied it became clear that the back of the dolphin was in fact a mixture of grey colours and that its underside was white. The scientific community are now universally agreed in naming the dolphin Chilean on account of its distribution along the coast of the country.

Conservation and whaling

The Chilean Dolphin is the only Cephalorhynchus not to readily ride the bow-waves of boats. This is believed to be due to wide-spread hunting by harpoon of the dolphins that occurred up until the early 1980s, causing individuals to become wary of boats. Up until hunting was banned around 1,300-1,500 individuals a year were killed. Nowadays a few individuals are lost each year in fishing equipment. It is possible, given the possible precariousness of the population, that these losses are causing an irreversible decline of the species, but this is not known with certainty.

References

• National Audubon Society: Guide to Marine Mammals of the World ISBN 0375411410
• Encyclopedia of Marine Mammals ISBN 0125513402