There are 43 species of dolphins found in the world. There are 38 marine dolphins, and 5 river dolphins. They live mainly in saltwater such as the oceans but some of them live in freshwater and they are able to do very well there. They tend to live in the shallow water by the coast and they tend to live in warmer locations. The name dolphin comes from the word womb, and it is believed to be the Greek saying for fish with a womb.