Appearance 
As a group, porpoises are known for their small, stocky bodies. They seldom ever grow beyond 6.5 feet (2 meters) in length, and only Dall’s Porpoise (which weighs in at 300-485 pounds, or 135-220 kilograms) regularly exceeds 150 pounds (68 kilograms) in weight. Unlike dolphins, they have no beaks, and can be recognized by their small, rounded heads. There is considerable variation in color from one species of porpoise to another, ranging from the mostly black Burmeister’s Porpoise, to the pale blue-gray Finless Porpoise.