While dolphins and sharks often share the same waters, sharks are quite different from other large ocean predators.
Sharks are cold-blooded fishes whose skeletons are made from cartilage instead of bone. Unlike bony fish, sharks teeth are not anchored in their jaw and sharks often lose teeth, especially when feeding. Sharks are equipped with three or more rows of teeth, so when a tooth is lost another tooth quickly replaces it. A single shark may have as many as 30,000 teeth throughout the course of its life.
Sharks eat far less than most people imagine. Cold-blooded animals have a much lower metabolism than warm-blooded animals. In fact, in a zoological environment, a shark eats about 1 to 10 percent of its total body weight each week. Studies on sharks in the wild show similar food intake.