Some of them are the tiger shark, great white, blue shark, nurse shark, and a whale shark. Sharks eat tuna, plankton, sardines, herring, small fish, and other sharks. Some sharks even eat swordfish. Sharks do not have bones. They have cartilage.
Cartilage is a rubbery lightweight material.
A shark's spinal column is made stronger with calcium layers. Sharks have at least five rows of teeth. They have very sharp teeth. Some can even slice through a turtle shell. Usually a shark loses one to two teeth at a time.