Which animal is also known as "susu"?

The Ganges river dolphin is a species of toothed whale classified in the family Platanistidae. It lives in the Ganges and related rivers of South Asia, namely in the countries of India, Nepal, and Bangladesh.

It is also known by the name "susu" (popular name) or "Sisu" (Assamese language) and "shushuk" (Bengali). The Ganges river dolphin has been recognized by the government of India as its National Aquatic Animal and is the official animal of the Indian city of Guwahati. Its first occurrence, within the Hooghly River, was documented by William Roxburgh.

The Ganges river dolphin has a rectangular, ridgelike dorsal fin and females tend to be larger than males. Ganges river dolphins usually are tan, chocolate brown or light blue. They have a large elongated beak with sharp and very pointed teeth, similar to most river dolphins. They have a large melon head used for echolocation, because they cannot see well. Their eyes are usually small due to the cloudy water. Ganges river dolphins are usually 2.2-2.6 meters long (7-8ft). The oldest recorded animal was a 28-year-old male, 199 cm in length.

The Ganges river dolphins usually come in pairs or they're just single and are not known to do acrobatic maneuvers near boats or when they're distressed. Little is known about their behavior because they are usually shy around boats and are hard to observe. They are known to breach; however this is rare.