Pink River Dolphin - WWF Factsheet

Posted on 30 June 2005
Scientific name: Inia geoffrensis de Blainville, 1817

Common names: Pink dolphin, boto (bugeo, bufeo, or tonina in the Orinoco region), also known as river dolphin.
The pink river dolphin has a robust yet very flexible body and a long beak, typical of the family. Sensory hairs are present on top of the beak, although they are more conspicuous in young and juveniles. Dentition is heterodont with incisors at the front of the jaw and molars at the back. The dorsal "fin" begins at the end of the first third of the body and is generally long and low, somewhat similar to a keel. Flippers are large and have a specially adapted joint with the scapula to allow a pronounced angle of rotation. Unlike the majority of dolphins, this species has free cervical vertebrae, allowing the head to be moved from side to side.
Colouration is variable within and between geographic areas. However, young are generally dark grey and either remain so as they grow older or turn greyish pink. It has also been reported that some grey dolphins can turn pink in a matter of minutes after intense physical activity, probably due to the species' thermoregulation strategies. Gestation can last up to 10 or 11 months and most young are usually born during the low water season or during the transition to high water.
River dolphins inhabit the drainage areas of the largest rivers in the world, mainly in developing countries. The pink river dolphin is widely distributed in the Amazon and Orinoco basins, in Colombia, Venezuela, Brazil, Ecuador and Peru. Currently, two species are recognised, Inia boliviensis in Bolivia and Inia geoffrensis, which contains two subspecies: I. geoffrensis geoffrensis in the Amazon and I. geoffrensis humboldtiana in the Orinoco.
Inia geoffrensis inhabits the Orinoco and Amazon river basins. The species is found in fast flowing lowland rivers, in both whitewater or turbid rivers originating in the Andes with high sediment content as well as clear water or blackwater rivers of Amazon origin. In the Orinoco basin, these dolphins are often found at confluences of different river types, in zones of mixed waters.

* Interaction with fisheries
* Dams and waterways
* Petroleum pollution
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