The term 'dolphin' can refer to two different aquatic mammals. The first is the DORADO, which is a large fish found in the Atlantic, Pacific, and Indian Oceans. It is also known as the mahi-mahi or dolphinfish. The second is the PORPOISE, which is a small toothed whale found in coastal waters around the world. Porpoises are related to dolphins, but are generally smaller and have a more rounded body shape.