The Franciscana dolphin, which is also called the La Plata River dolphin, is one of the rarest dolphins in South America. Due to its rarity, there is little known about it.

It grows to be between 4 and 6 feet long, and weighs up to 115 pounds, and its body is a grayish brown color.

Even though sightings of the Franciscana dolphin are scarce, it can be found in the Doce River, in Brazil, and the Peninsula Valdes in Argentina. It can also be found in the coastal waters of Uruguay.

This is the only species of river dolphins that can be found in salt water.

The Indus River dolphin is gray-brown, with a pink belly. It grows to be between five and eight feet, and can weigh up to 200 pounds.

The Indus River dolphin is only known to exist in the Punjab Province and the Sind Province of the Indus River.

Due to its decline in population, the government of Sind, in Pakistan, has given the Indus River dolphin full legal protection, and has also established the Indus River Dolphin Reserve.

The Ganges River dolphin is closely related to the Indus River dolphin. It also grows between 5 and 8 feet, and can weigh up to 200 pounds.

It can only be found in the fresh water rivers of Bangladesh, India, and Nepal.

These dolphins are commonly poached for their oil, which is used in the preparation of bait. Even though the Ganges River dolphin's existence is threatened, little has been done to protect it.

The Yangtze River dolphin, commonly known as the Chinese River dolphin or the Baiji dolphin, is at the brink of extinction.