The eye and optic nerve of the Ganges river dolphin are degenerate. The eye lacks a lens and is therefore incapable of forming images on the retina. However, it functions in light-detection. Reproduction Young are born year-round in this species, but most births occur between October and March. A significant birth peak takes place in December and January, at the beginning of the dry season.
Gestation lasts eight to nine months.
The young are weaned and solitary before they are one year old. Behavior Although schools of three to ten individuals have been reported in particular parts of river systems, these animals are not gregarious and spend most of their time feeding and travelling solitarily. They swim all day and all night and continually emit sounds. The Ganges river dolphin is found only in fresh water and may migrate locally to tidal waters during the monsoon season. Habitat Platanista gangetica lives in the muddy waters of the Ganges, Brahmaputra, Meghna, Karnaphuli, and Hoogly river systems.