South Asian river dolphin.
South Asian river dolphins are toothed whales in the genus Platanista. They inhabit fresh water habitats in the northern Indian subcontinent. They were historically considered to be one species, but the Ganges river dolphin (pictured) and the Indus river dolphin were described as separate species in 2021, having diverged around 550,000 years ago. South Asian river dolphins are small but stocky cetaceans with long snouts or rostra, broad flippers, and small dorsal fins. Living in murky river waters and relying on echolocation for navigation, they have tiny, lensless eyes. The skull has large crests over the melon, which help direct their echolocation signals as they prey, mainly on fish and shrimp. They are active throughout the day in small groups. Both species are listed as endangered mammals by the IUCN Red List. Major threats include dams, barrages, fishing nets, and both chemical and acoustic pollution.
