| Chilean Dolphin | ||||||||||||||||||
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| Cephalorhynchus eutropia |
The Chilean Dolphin, which despite the name falling out of favour in scientific circles is still sometimes known as the Black Dolphin, is one of four dolphins in the Cephalorhynchus genus. The dolphin is only found off the coast of Chile.
The Dolphin is normally sighted in small groups of around 2 to 10 individual, 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.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 individuals studied by scientists were either dead, washed-up specimens whose skin hard darkened due to exposure to air or those seen at sea who were rarely at close quarters and at a distance appeared to be darker than was in fact the case. 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.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 Valparaiso 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-following tidal areas and mouths of rivers.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.