Which Amazon Rainforest mammal is the world’s largest freshwater dolphin?

The Amazon river dolphin is the world’s largest freshwater dolphin.

Also called the pink river dolphin or boto, it lives in the Amazon and Orinoco river systems. Adults can reach about 2.5 metres in length and weigh more than 150 kilograms, although size varies by region and sex. Its flexible neck and broad flippers help it manoeuvre through flooded forests and around submerged roots.

The species is not uniformly pink. Young dolphins are usually grey, while adults may become pinker with age, scarring and blood-vessel visibility. Males are often larger and more heavily marked than females.

The Amazon river dolphin is different from the tucuxi, another Amazonian dolphin that generally has a slimmer body and more typical grey colouring. During high-water seasons, botos enter flooded forests to hunt fish, crustaceans and other prey among the trees.