Also known as pink boto, the red boto is the largest of the world’s freshwater dolphins, measuring from 2 to 2.5 m and weighing from 100 to 200 kg. It has a coloration that varies from light gray in puppies and young, the bright pink in adults. Males are much larger and rosier than females. It feeds mainly on fish and is usually solitary. The main cause of mortality is accidental catch in fishing nets.
Intentional deaths occur due to the species’ behavior in removing fish from the nets. Another threat is the direct capture of boto for use as bait in the fishing of the piracatinga (Callophysus macropterus), which has been reducing the populations of porpoises along the Solimões and Japurá channels, studies indicate a decrease of 7% per year in some regions of the Amazon. The species is listed as endangered by IUCN.