There is also a sixth sense that allows sharks to detect weak electrical signals generated by their prey. Smell is a shark's most acute sense. Approximately 70 percent of the shark's brain is used for smelling. Sharks' diets vary considerably and may include plankton, clams, crabs, sea turtles, fishes, seals, porpoises, and whales. For some sharks, finding a mate means a long swim, because males and females often live in different pars of the ocean.
Sharks continually loose their teeth.
When the front ones wear out they are replaced by new ones. Sharks teeth come in many shapes according to what kind of food they eat. The shapes are spiked for gripping small prey, serrated for cutting, long curved teeth for holding slippery fish, and blunt teeth for crunching up shell fish like turtles. There are many types of sharks. The Great White shark is a powerful predator.