A few species enter rivers and lakes that have outlets to the sea. Scientists believe that one species, the Ganges River shark of India and Pakistan, lives only in rivers. Most of them eat live fish, including other sharks. In fact, a shark's most common natural enemy is a larger shark. Most sharks eat their prey whole, or they tear off large chunks of flesh.
Some sharks crush their prey.
Others scoop out small pieces of flesh from large fish. Sharks also feed on dead or dying animals. Sharks have the reputation of attacking human beings. But fewer than 100 shark attacks a year are reported throughout the world. Sharks differ from most other kinds of fish in a number of ways.