Setting the interfamilial variations aside for a moment, the average shark dines on fish, squid and crustaceans [source: Parker]. When it comes to more specific diet preference, here are some favorites of individual shark species:
Interestingly, the largest shark species, the whale shark, does not hunt at all. Enormous whale sharks, megamouth sharks and basking sharks filter feed on plankton. These species have specialized gills that sift through water to extract the microscopic algae and sea creatures that comprise plankton. Just by indiscriminately taking water into their mouths, basking sharks filter 528,000 gallons of water each hour, extracting 4.5 pounds (2 kg) of food [source: Parker].
Some larger, faster sharks extend their diet to include sea mammals, in addition to substantial fish such as tuna, mackerel and other sharks. Great white sharks, tiger sharks and mako sharks may also consume seals, sea lions, sea birds, dolphins and porpoises.
Tiger sharks are probably the least discriminating in their culinary tastes. Stomach contents from tiger sharks have included license plates, turtles, sea snakes and gasoline canisters [source: Discovery Channel].
If you aren't sure what type of food a certain shark species eats, check out its mouth. Different sharks have specialized teeth tailored to their preferred prey. Great whites have razor-sharp, triangular fangs to slice through the thicker, fattier flesh of larger fish and sea mammals. Since tiger sharks enjoy crustaceans, their teeth resemble steak knives with serrated edges and a rounded shape to break through the shells. Filter feeders like whale sharks have row upon row of short, blunt teeth since they don't have to rip through anything [source: Parker].
But despite sharks' reputation for voracious appetites, they may be the target of something else's mealtime cravings. Find out on the next page when sharks become prey.