The body is fusiform with gill slits on both sides of the head, but it resembles a common fish. With a few exceptions, the typical shark has hard, dark gray skin with tooth-like scales that make the skin appear rough. The tail is strong and powerful, asymmetrical and upturned; the fins are pointed; the snout is pointed and protruding, with a crescent-shaped mouth and triangular fangs under the snout. Sharks have no swim bladders and need to swim constantly to avoid sinking to the bottom.
