A. Food Preferences an Resources:
Sharks and batoids eat almost anything: fishes, crustaceans, marine mammals, mollucs and other sharks. Sharks are not very selective feedres but some sharks like the hammerhead are known for eating stingrays, bull sharks for eating other sharks and smooth dogfish for eating crustaceans.
Tiger sharks are called the trash cans of the sea because they eat anything. Tiger sharks are ecologically important predators of sea turtles and sea snakes. Sharks usually eat only slow, ill or sick prey.
B. Food Intake:
Studies showed that sharks eat about 1% to 10% of its total body weight per week.
C. Methods of Collecting and Eating Food:
A sharks teeth is adapted to its diet and due to the huge biting force of the shark the teeth breaks easily. Teeth are replaced, as soon as one falls out, by reserve rows. Most predatory species seize and tear their food. A shark’s lower jaw is hinged at two points on the skull and when it feeds the lower jaw extends and grab the prey while the top jaw slices the prey. Some species of sharks and batoids are bottom feeding and use the top jaw to help pick up prey items. The teeth may be fused into plates or front teeth may be pointed while the back teeth are flat molarlike for crushing.
Another method of feeding is filter feeding. Some species which exibit this is the whaleshark, basking shark and manta ray. By using gill rakers or spongy tissue between the gill slits, They trap plankton.