Population & Distribution
Total river dolphin population in India: 6,327 (as per Environment Ministry study).
Types of River Dolphins:
Facultative river dolphins: Found in both fresh and marine waters.
Example: Irrawaddy dolphins in Chilka Lake (155 individuals) and Sunderbans.
Obligate river dolphins: Found only in freshwater.
Example: Ganges river dolphin (widespread in Ganges & Brahmaputra).
Indus river dolphin: State aquatic animal of Punjab, found in Beas River and Harike wetlands.
Study found only 3 individuals, indicating near extinction in India.
Pakistan has around 1,800 Indus dolphins.
Unique Adaptations
Poor eyesight:
Eyes are only 1 cm across, lack lenses, and can barely detect light direction.
Echolocation reliance:
Uses "melon" (fatty forehead mass) to focus sound waves for navigation and hunting.
Can detect objects as small as 4 mm in experimental conditions.
Prefers muddy, low-salinity waters.
Unusual swimming habit:
Often swims on its side, using fins to feel along the riverbed for food.
Threats & Conservation Needs
Poaching for oil, used in traditional remedies.
Overfishing, reducing food supply.
Accidental entanglement in fishing nets (bycatch).
Pollution from chemicals and industrial waste.
Population trends unclear, but numbers are critically low.
Urgent need for public awareness and conservation efforts.
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