Gangetic Dolphins
- The survey, conducted since 2021, covered 8,507 km across Uttar Pradesh, Bihar, West Bengal, and Assam.
- Maximum number of dolphins were found in Uttar Pradesh, followed by Bihar, West Bengal, and Assam.
- The study relied on acoustic hydrophones and triangulation methods for dolphin detection.
- About Gangetic Dolphins:
o Common Names: Ganges river dolphin, blind dolphin, Ganges susu, Hihu, Bhagirath.
- Conservation Status: IUCN – Endangered, WPA - Schedule – I, CITES - Appendix - I
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- Distribution: Historically found in Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of India, Nepal, and Bangladesh.
o Restricted to disjunct stretches in India’s Ganga-Brahmaputra-Barak river system, Nepal’s Karnali, Sapta Koshi, Narayani Rivers, and Bangladesh’s Meghna, Karnaphuli, Sangu rivers.
o Recorded in mainstream Ganga River and tributaries like Ghaghra, Kosi, Gandak, Chambal, Rupnarayan, and Yamuna.
- Characteristics, Habitat, and Behaviour:
o Physical features: Long thin snout, rounded belly, stocky body, large flippers, and a slit-like blowhole.
o Sexual dimorphism: Females larger than males; give birth once every 2-3 years to a single calf.
o Coloration: Calves have chocolate brown skin at birth; adults have grey-brown, smooth skin.
o Freshwater species, essentially blind, using ultrasonic sound waves (echolocation) to hunt.
Detailed Solutions & Explanations
