There are five known species of river dolphins in the world. Unlike their relatives, the oceanic dolphins, river dolphins live in fresh water. There are four families that are all grouped together under the superfamily Platanistoidea. The families are:
- Iniidae (Amazon River Dolphin)
- Lipotidae (Chinese River Dolphin)
- Platanistidae (Ganges River Dolphin and Indus River Dolphin)
- Pontoporiidae (La Plata Dolphin)
Some dolphin species can live in marine or riverine environments. The Tucuxi, for example, is equally at home in both ecotypes. However these are not classified in the Platanistoidea superfamily and are not regarded therefore as true river dolphins.
For more information, see the articles on the individual species