Dolphins and porpoises are both aquatic mammals belonging to the cetacean family of animals. Dolphins have a more curved, streamlined body shape than porpoises, and are considerably bigger in size. Porpoises tend to have a more rotund, stocky body shape than dolphins. The dorsal fin on a porpoise is triangular in shape, whereas the dorsal fin on a dolphin is curved or hooked. In terms of colouration, dolphins are typically grey with lighter patches on the belly, whereas porpoises tend to be dark grey or black. The most well-known distinction between dolphins and porpoises is the shape of their teeth; dolphins have conical teeth whereas porpoises have spade-shaped teeth. Dolphins are very social animals, often seen swimming in pods and interacting with each other. Porpoises, on the other hand, tend to be solitary creatures and are rarely seen in groups. Dolphins are also much more vocal than porpoises, and use a variety of sounds including clicks, whistles, and squeaks to communicate with each other.