Porpoise and dolphin are often used interchangeably as general terms for small toothed whales. These animals are found in every ocean of the world. Killer whales, melon-headed whales, pilot whales, and false killer whales are all part of the dolphin family, but are called whales because of their size.

Dolphins and porpoises are carnivores, with most eating fishes and/or squids. Different habitats mean different diets; each type of dolphin and porpoise specializes in catching prey that lives in its specific ecosystem.

A dolphin is a relatively small cetacean, usually with a curved dorsal fin – the raised structure on the back of most cetaceans. Dolphins are generally about six–12 feet long, and have melon-shaped heads with beaks. Their teeth are cone-shaped, and top and bottom teeth interlock. Dolphins move in large, more socially complex pods than porpoises and tend to be more acrobatic at the surface.

Porpoises have stocky bodies, blunt heads and small, spade-shaped teeth. They’re the smallest cetaceans at about four–seven feet in length.