The river dolphin's eye is reduced to a pinhole opening with no crystalline lens. It can probably detect the direction and intensity of light, but not shapes. In water carrying heavy silt for much of the year, an image-forming eye would earn little anyway.
Instead the animal echolocates continuously, sweeping the head as it swims. The characteristic posture is a side swim, body rolled roughly ninety degrees with one flipper skimming the bottom, apparently helping it track the riverbed and flush prey such as catfish, prawns and small carp from the sediment. Individuals surface every thirty to ninety seconds.
The species has been reorganised recently. Populations in the Indus were long treated as a subspecies, and in 2021 genetic and morphological work supported recognising the Indus river dolphin as a separate species, though the treatment is not universally adopted and older sources still list a single species with two subspecies.