Despite the reputation given this species by Hollywood, humans are not the preferred prey of the great white shark. It is the largest predatory fish in the world feeding on marine mammals such as seals, sea lions and dolphins as well as other fish. It can reach a length of up to 20 feet and weigh as much as 4,000 pounds. This species name refers to its white belly. The teeth in the upper jaw are sharp, serrated triangles, while those in the lower jaw are smaller and weakly serrated.