
© Alamy-Nature Picture Library
River Dolphin
A unique group of cetaceans, river dolphins are the only cetacean species that lives in freshwater, all others residing in saltwater. These animals are not widely distributed and are only found in certain rivers or deltas in either South America (in the Amazon Basin) or Asia and China, depending on the species. There are six different species, but all have distinguishing characteristics that set them apart from their saltwater cousins. They have very small eyes, long beaks, and instead of a distinct dorsal fin, they have more of a hump on their backs.