* The Amazon River Dolphin (Inia geoffrensis): Also known as the "boto," this dolphin is found in the Amazon and Orinoco river basins.
* The Ganges River Dolphin (Platanista gangetica gangetica): This species is found in the Ganges and Brahmaputra rivers in India, Bangladesh, and Nepal.
* The Indus River Dolphin (Platanista gangetica minor): This species is found in the Indus River in Pakistan.
* The Baiji (Lipotes vexillifer): This dolphin was found only in the Yangtze River in China. It is believed to be extinct.
* The La Plata Dolphin (Pontoporia blainvillei): While this species is often called a "freshwater dolphin," it actually lives in brackish water, where rivers meet the ocean.
It's important to note that while all these species are called "dolphins," they are not closely related to the oceanic dolphins. They belong to different families and have evolved independently to inhabit freshwater environments.