Sharks have ruled Earth's oceans for more than 450 million years - and they still do today! Why are sharks so successful? How do they hunt, and what do they eat? How do you tell a shark's age? What is the biggest shark and how small is the smallest shark? Learn answers to these questions and more in this book full of facts and photographs. Dive into the undersea world of the great white, hammerhead, leopard, angel, whale, and other remarkable sharks.