Gangetic River Dolphin

About Gangetic River Dolphin

• It is a freshwater species and one of the few river dolphins found in the world.
• Distribution: It inhabits the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh.
• Common Names: Blind dolphin, Ganges dolphin, Ganges susu, hihu, side-swimming dolphin, South Asian River Dolphin
• It has been recognized as India's National Aquatic Animal.

Features:

• It has a long thin snout, rounded belly, stocky body and large flippers.
• It feeds majorly on fishes and is usually found in counter-current systems of the main river channel.
• Its eyes lack lens, and as a result, this species is also referred to as the "blind dolphin".
• They have a highly developed bio-sonar system that facilitates them to hunt for fish even in murky waters.
• Being a mammal, the Ganges River dolphin cannot breathe in the water and must surface every 30-120 seconds. Because of the sound it produces when breathing, the animal is popularly referred to as the 'Susu'.

Conservation status:

• IUCN: Endangered
• Wildlife (Protection) Act: Schedule-I 
• CITES: Appendix I

Q1: What is a bio-sonar system?

A bio-sonar system, also known as echolocation, is a sensory system used by certain animals, primarily in the animal kingdom, to navigate and locate objects in their environment by emitting sound waves and interpreting the echoes that bounce back. This ability allows these animals to perceive their surroundings in complete darkness or low-light conditions, or even in murky water where visibility is limited.

Source: 19 dolphins rescued alive from canals of Ganga-Ghagra basin, says study