Platanista – Asian river dolphin

The South Asian river dolphins are flagship species, powerful indicators of the biodiversity present in their riverine homes

Asian River Dolphins have two distinct sub-species, the Ganges River Dolphin (Platanista gangetica gangetica) and the Indus River Dolphin (Platanista gangetica minor), that inhabit the intricate river systems of South Asia. These species are uniquely adapted to life in the turbid, sediment-laden waters of the Ganges and Indus rivers, showcasing a suite of specialized adaptations that underscore their evolutionary journey.

Characterized by their elusive nature, these dolphins are often found swimming solitarily through the winding channels and vast stretches of their freshwater habitats. One of the most remarkable adaptations of these species is their functional blindness. The murky waters of the Ganges and Indus rivers offer little visibility, rendering eyesight less useful. Over millennia, these dolphins have evolved to rely almost entirely on acoustic echolocation for navigation, communication, and hunting. This sophisticated biological sonar system allows them to emit sound waves that bounce off objects and return echoes, providing the dolphins with a detailed “picture” of their surroundings.

Another distinctive behavior of Asian river dolphins is their lateral swimming posture. Unlike most dolphin species that swim upright, the Ganges and Indus river dolphins navigate their aquatic environment on their sides. This unique swimming style, coupled with one of their flippers occasionally brushing against the riverbed, aids in locating prey hidden in the soft river bottoms. Their elongated snouts are perfectly adapted for snapping up small fish and crustaceans, which constitute the bulk of their diet.

The flexibility of their necks is another evolutionary adaptation that sets these dolphins apart from their marine counterparts. This anatomical feature enables them to maneuver adeptly through the complex network of narrow tributaries, dodge obstacles like tree roots, and navigate the dynamic river ecosystems they call home.