The Amazon River Dolphin is a freshwater river dolphin endemic to the Orinoco, Amazon, and Araguaia/Tocantins River systems of Brazil, Peru, Bolivia, Ecuador, Colombia and Venezuela. It is listed as Endangered by the IUCN due to pollution, overfishing, excessive boat traffic and habitat loss.
Other common names of the species include boto, bufeo, lo lo annaaaa, boto cor-de-rosa,bouto, and pink dolphin.
The Amazon river dolphin is one of a handful of river dolphins included in the paraphyletic group classified as the superfamily Platanistoidea. Although not a large cetacean in general terms, this dolphin is the largest cetacean to spend most of its life in freshwater; it can grow larger than a human. Body length can range from 1.53 to 2.4 m (5.0 to 7.9 ft), depending on subspecies. Females are typically larger than males. The largest female Amazon river dolphins can range up to 2.5 m (8.2 ft) in length and weigh 98.5 kg (217 lb). The largest male dolphins can range up to 2.0 m (6.6 ft) in length and weigh 94 kg (210 lb).
They have unfused neck vertebrae, enabling them to turn their heads 180 degrees. Their flexibility is important in navigating through the flooded forests. Also, they possess long beaks which contain 24 to 34 conical and molar-type teeth on each side of the jaws.
The Amazon river dolphin is found throughout the Amazon and Orinoco. It is particularly abundant in lowland rivers with extensive floodplains. During the annual rainy season, these rivers flood large areas of forests and marshes along their banks. The Amazon river dolphin specializes in hunting in these habitats, taking advantage of its unusually flexible neck and spinal cord to maneuver among the underwater tree trunks, and using its long snout to extract prey fish from hiding places in hollow logs and thickets of submerged vegetation.
When the water levels drop, the dolphins move either into the main river channels or into large lakes in the forest, and take advantage of the concentrated prey in these reduced water bodies. They feed on crustaceans, crabs, small turtles, catfish, piranha, shrimp, and other fish.