Home > Ganges and Indus River Dolphin
Ganges and Indus River Dolphin
Endangered |
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Ganges River Dolphin
Photographer:Brian D. Smith |
| Scientific classification |
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| Binomial name |
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Platanista gangetica
Platanista gangetica gangetica
Platanista gangetica minor
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Ranges of the
Ganges River Dolphin
and of the
Indus River Dolphin.
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The Ganges River Dolphin (Platanista gangetica gangetica) and Indus River Dolphin (Platanista gangetica minor) are two sub-species of freshwater or river dolphins found in the Indian sub-continent. From the 1970s they had commonly been regarded as separate species. However in 1998, a seminal work on cetacean taxonomy listed them as a single species once again (see taxonomy below). The single species is likely to have either the Ganges and Indus River Dolphin or Indian River Dolphin as its common name, although neither has yet spread into wide usage and the latter does not reflect that the Indus subspecies is resident primarily in Pakistan.
1 Other names
- Both subspecies: Blind River Dolphin, Side-swimming Dolphin, Susu
- Ganges subspecies: Gangetic Dolphin, Ganges Susu
- Indus subspecies: Bhulan, Indus Dolphin, Indus Susu
2 Taxonomy
Until the 1970s the Indus and Ganges River Dolphins were regarded as a single species, first named by Roxburgh in 1801. However at that time it became clear that two populations, one centered on the Ganges River in India and the other in the Indus River in Pakistan had not interbred for many hundreds of years. Based on differences in skull structure, scientists declared the two populations as separate species. However Rice, in his taxonomic classification of cetaceans that has become standard in the field, [1], found that there were insufficient morphological differences to warrant distinction at the species level. Thus just one species is recognised in the genus Platanista and four true river dolphin species, each in its own family as well as genus.
3 Physical description
The Ganges and Indus River Dolphins are essentially identical in appearance. They have the long, pointed snout characteristic of all river dolphins. Both the upper and lower jaw sets of teeth are visible even when the mouth is closed. The snout thickens towards its end. The species does not have crystalline eye lens, rendering it effectively blind, although it may still be able to detect the intensity and direction of light. Navigation and the hunt for food is carried out using echo-location. The body is a brownish colour and stocky at the middle. The species has only a small triangular lump in the place of a dorsal finDorsal Fin of the Orca A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises. Its main purpose is to stabilise the animal against rolling and assist in sudden turns. Some animals have developed dorsal fins with protective fu. The flippers and tail are thin and large in relation to the body size, which is about 2-2.2 mFor other uses of "metre" and "meter", see Metre (disambiguation). The metre is the basic unit of length in the International System of Units (SI: Systeme International d'Unites). It is defined as the length of the path travelled by light in absolute vacu in males and 2.4-2.6m in females. The life span and other life history data is unknown.
The species feeds on shrimp and small fish that prefer the waters close to the river bed. Dolphins are usually encountered on their own but have travelled in groups more often historically, when populations were larger.
