South Asian River Dolphin (Platanista)
Since the 1970’s and until 1998 the South Asian River Dolphin was considered to be two separate species, the Indus River Dolphin (Platanista gangetica minor), and the Ganges River Dolphin (Platanista gangetica gangetica). This was due to differences in skull structure, vertebrae and lipid composition.
However, in 1998 the classification changed and they are now considered the only two subspecies of the genus Platanista. Externally, the two subspecies look identical, but they are geographically separated around the great rivers that have given them their names.
Among all cetaceans, the South Asian River Dolphin is the only one lacking a crystalline eye lens, thus making it blind. Instead, the species find food using echolocation.
Uniquely among cetaceans, the South Asian River Dolphin swim on one side, usually by leaning to the right and cruising near the bottom of the river.