Owen, 1853- Indus River dolphin
Distinctive Characteristics
Indus River dolphins, or bhulan, are almost identical in external appearance to Ganges River dolphins. In fact, some researchers believe that the 2 types would be most appropriately classified as subspecies of Platanista gangetica. The most distinctive characteristics are the robust body, low dorsal fin, long beak, small eyes, longitudinal blowhole, and elongated front teeth.
Can be confused with
Although their ranges generally overlap only in a small portion of the lower Indus, Indus River dolphins might be confused with Irrawaddy dolphins, finless porpoises, bottlenose dolphins, and Indo-Pacific hump-backed dolphins. The dorsal fins of bottlenose and hump-backed dolphins, complete lack of a dorsal fin in finless porpoises, and absence of a beak in Irrawaddy dolphins should make them distinguishable. Also, bottlenose and hump-backed dolphins are much larger.
Size
Indus River dolphins probably grow slightly smaller than the maximum sizes of 2.6 m (females) and 2.2 m (males) for Ganges River dolphins. Length at birth is between 70 and 90 cm.
Geographical Distribution
Though formerly more widely distributed in the Indus and some of its tributaries, the range is now restricted to the middle and lower Indus River. It is centered between Jinnah and Kotri barrages.
Biology and Behaviour
Although most commonly seen singly or in very small groups, Indus River dolphins have been reported in loose aggregations of up to 30 individuals. Like their relatives in the Ganges River, they often swim on their sides and appear to navigate mainly with the aid of echolocation.
There is almost nothing known of the reproductive biology of this species. Newborns have been observed in April and May.
Indus River dolphins feed on prawns and several species of fish. They may do much of their feeding on or near the bottom.
Exploitation
The Indus River dolphin is now extirpated in many parts of its former range. Both incidental and direct catches, as well as various forms of habitat destruction (including damming, diversion, and contamination of rivers) represent threats to the survival of the Indus River dolphin.
IUCN Status
Endangered.