Habitat
Ganges River Dolphins prefer deep waters, in and around the confluence of two or more rivers. They share their habitat with crocodiles, fresh water turtles and wetland birds.
Distribution
The distribution range of the Ganges River Dolphins in India covers seven states namely, Assam, Uttar Pradesh, Madhya Pradesh, Rajasthan, Bihar, Jharkhand and West Bengal. The Upper Ganga River (in Uttar Pradesh), Chambal River (Madhya Pradesh and Uttar Pradesh), Ghaghra and Gandak Rivers (Bihar and Uttar Pradesh), Ganga River, from Varanasi to Patna (Uttar Pradesh and Bihar), Sone and Kosi rivers (Bihar), Brahmaputra from Sadia (foothills of Arunachal Pradesh) upto Dhubri (on the Bangladesh Border) and Kulsi River, a tributary of the Brahmaputra river, form ideal habitats for the Ganges River Dolphin.
Characteristics
The Ganges River Dolphin has a sturdy, yet flexible, body with large flippers and a low triangular dorsal fin. It weighs upto 150 kg. The calves are chocolate brown at birth and becomes greyish brown in adulthood with a smooth and hairless skin. Females are larger than males. The maximum size of a female is 2.67m and of a male 2.12 m. Females attain sexual maturity at an age of 10-12 years, while the males mature earlier. The gestation period is 9-11 months and a female gives birth to only one calf, once in 2-3 years.
Dolphins are amongst one of the oldest creatures in the world along with some species of turtles, crocodiles and sharks. The Gangetic Dolphins are generally blind and catch their prey in a unique manner. They emit an ultrasonic sound which reaches the prey. The dolphin then registers this image in its mind and subsequently catches hold of its prey.