The freshwater dolphins found in the Ganga and Brahmaputra rivers are commonly known as:

The Ganges river dolphin (Platanista gangetica) is locally called "susu" or "soons", from the puffing sound it makes when it surfaces to breathe.

National Aquatic Animal:

The Government of India declared the Ganges river dolphin the National Aquatic Animal in October 2009.

Where it is found:

• It lives in the Ganga-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of India, Nepal and Bangladesh.
• In India, it is found in Uttar Pradesh, Bihar, Jharkhand, West Bengal and Assam, as well as in rivers such as the Chambal, Ghaghara, Gandak, Kosi and Son.
• Bihar has the largest population.

Special features:

It is practically blind. Its eyes lack lenses and can only detect light and its direction.

It finds its way and its prey using echolocation, producing ultrasonic sounds and listening to the echoes.

It has a long, thin snout with many sharp teeth.

It must surface every 30 to 120 seconds to breathe.

It is a good indicator of the health of the river, since it needs clean, deep and flowing water.

Conservation status:

• It is listed as Endangered on the IUCN Red List.
• It is protected under Schedule I of the Wild Life (Protection) Act, 1972.

Threats:

• Construction of dams and barrages, which fragment its habitat.
• Pollution, sand mining, accidental capture in fishing nets and hunting for its oil.

Conservation efforts:

• The Vikramshila Gangetic Dolphin Sanctuary in Bhagalpur, Bihar, is the only protected area in India dedicated to the Gangetic dolphin.
• Project Dolphin was announced in 2020 to conserve river and ocean dolphins.
• 5 October is observed as National Dolphin Day.
• A national survey released in 2025 estimated about 6,300 river dolphins in India.

Other dolphins:

The Indus river dolphin, called "bhulan", is found in Pakistan and in the Beas river in Punjab (India).

Why not the other options?

• ✗Bhulan is the Indus river dolphin.
• ✗Humpback and bottlenose dolphins are marine dolphins.