Boto is a Portuguese name used to identify several types of dolphins and river dolphins native to the tributaries of the Amazon and Orinoco Rivers. These dolphins are notable for inhabiting various environments, with some species existing exclusively in freshwater systems.
The Boto dolphin is characterized by its distinct pink coloration, which typically intensifies as the animal ages. This change in color is caused by scar tissue developing across the body throughout their lives. In males, the degree of pinkness serves as a sign of maturity, functioning similarly to the antlers of red deer or the tusks of narwhals. During adolescence, these dolphins often lose pigment and appear light pink before maturing.