Quck answer
Most sharks are carnivores and feed on a variety of prey including fish, squid, crustaceans, and marine mammals. Some species of sharks, such as the whale shark, feed on plankton. Other sharks, such as the tiger shark, are known to be opportunistic feeders and will eat almost anything they come across, including garbage and even other sharks. Overall, the diet of a shark depends on the species, habitat, and availability of prey in their environment.
Wild Animals
Generally, sharks prefer to consume fish, crustaceans, and squid. With almost 400 shark species, their individual dietary habits vary. For instance, the cookiecutter shark takes nonlethal bites of flesh from their prey, while great white sharks may consume large sea mammals in one swallow. The dietary habits of the 8-inch (20-centimeter) dogfish shark differ from that of the 60-foot (20-meter) whale shark, and each cousin, aunt, and uncle in between has its own dietary preference.
Shark Image Gallery
All sharks are carnivorous to some extent, and they usually eat between 0.5 to 3.0 percent of their body weight per meal. Since they cannot chew well, they require time to digest their food properly [source: Cawardine]. They space out their meals every two to three days.
If large sharks were to die out, that would increase the population of octopus, which would feed on more lobsters [source: New York Times]. Therefore, their diets play an important role in regulating the species below them, much like lions in the jungle. Moreover, shark hunting habits help to maintain a survival of the fittest mode in their environment. To conserve energy, sharks often prey on weak, immature, or sickly fish or mammals [source: Parker]. This eliminates the more vulnerable creatures and keeps the stronger, healthier fish and animals alive.
What specific fish and mammals do sharks eat? Discover this on the following page.
В
Shark Dietary Variations
Meals made easy. A whale shark filter feeds with its mouth wide open.
Thomas Schmitt/Getty Images
Setting aside the interfamilial variations, the average shark feeds on fish, crustaceans, and squid [source: Parker]. Here are some favorite food items of individual shark species:
- Hammerheads feed on stingrays.
- Smooth dogfish sharks prefer crabs and lobsters.
- Tiger sharks eat sea turtles.
- Blue sharks like squid.
[source: SeaWorld]
Interestingly, the largest shark species, the whale shark, does not hunt. Enormous whale sharks, megamouth sharks, and basking sharks filter feed on plankton. These species have specialized gills that extract microscopic algae and sea creatures that constitute plankton. By taking water into their mouths, basking sharks filter 528,000 gallons of water per hour, extracting 4.5 pounds (2 kg) of food [source: Parker].
Some larger, faster sharks consume sea mammals, besides substantial fish such as tuna, mackerel, and other sharks. Great white sharks, tiger sharks, and mako sharks may also eat seals, sea lions, sea birds, dolphins, and porpoises.
Tiger sharks are likely the least choosy in their culinary tastes. Stomach contents from tiger sharks have included license plates, turtles, sea snakes, and gasoline canisters [source: Discovery Channel].
The food preferences of different shark species can be determined by examining their mouths. Sharks have teeth that are specially adapted to their preferred prey. Great whites, for example, have sharp, triangular teeth that can cut through the thick, fatty flesh of larger fish and sea mammals. Tiger sharks, on the other hand, have serrated teeth with a rounded shape, which enable them to break through crustacean shells. Filter feeders like whale sharks have short, blunt teeth in row after row since they do not need to rip through anything. Despite their reputation as voracious eaters, sharks can also become prey for other creatures. Killer whales, crocodiles, seals, and other sharks may prey on younger sharks, while humans are their most significant predator. Shark meat has become increasingly popular, and their cartilage is also used in some medicines. As a result, certain shark species populations have dwindled, with experts estimating that their overall numbers have dropped by as much as 90 percent. However, shark attacks are relatively rare, with only around 30 of nearly 400 species making contact with humans. Of those 30, only about a dozen are considered potentially harmful to people.
Answers to Common Questions About Shark Diets
What is the preferred food of sharks?
Sharks are carnivorous and consume invertebrates as well as large sea mammals, such as dolphins and seals. Some species of sharks prey on tuna, mollusks, squid, mackerel, crustaceans, and stingrays.
Why isn’t shark meat popular?
Shark meat is consumed in some parts of the world but not in North America. It is not commonly eaten due to high mercury levels, and many shark species are also classified as endangered.
Can people hunt sharks in the United States?
Hunting sharks is prohibited in the United States under the Shark Conservation Act. Removing their fins while they are alive and then throwing them back into the water is also illegal.
Do sharks eat humans?
Although sharks are predators, they rarely attack humans and almost never eat them. They may attack if they feel threatened or confused, but their main diet consists of marine mammals and fish.
Additional Information
Related Articles
- How Sharks Work
- How Great White Sharks Work
- How Bull Sharks Work
- How Tiger Sharks Work
- How Nurse Sharks Work
- How Shark Attacks Work
- How Sharks Smell, Hear and See?
- 15 Tips for Surviving a Shark Attack
- Why Do People Collect Shark Teeth?
- Could Shark Cartilage Help Cure Cancer?
More Great Links
- Discovery Channel Shark Guide
- Florida Museum of Natural History — Ichthyology Department
- International Shark Attack File
Sources
- Carwadine, Mark. “Shark.” Firefly Books. 2004. (May 14, 2008)http://books.google.com/books?id=Qh44RNa5yh0C
- International Shark Attack File. “The Relative Risk of Shark Attacks to Humans.” Florida Museum of Natural History. Updated June 2007. (May 27, 2008)http://www.flmnh.ufl.edu/fish/Sharks/attacks/relarisk.htm
- Lloyd, Robin. “Sharks Decline But Attacks Rise.” LiveScience. Feb. 27, 2008. (May 15, 2008)http://www.livescience.com/animals/080227-aaas-sharks.html
- Kelly, Erin. “For Sharks, Real People are Predators.” Gannett News Service. Aug. 4, 2003.
- Klimley, A. Peter. “The Predatory Behavior of the White Shark.” American Scientist. March/April 1994.
- National Marine Fisheries Service. “Imports and Exports of Fisheries Product Annual Summary, 2007.” US Department of Commerce. (May 15, 2008)http://www.st.nmfs.noaa.gov/st1/trade/documents/TRADE2007.pdf
- National Oceanic and Atmospheric Administration. “Our Fear of and Fascination with Sharks.” NOAA Magazine. June 3, 2002.
- New York Times. “Great White Shark: Fierce But Necessary.” Aug. 8, 1986.
- Parker, Jane and Parker, Steve. “The Encyclopedia of Sharks.” Firefly Books. 2002.
- SeaWorld. “Sharks Background Information. August 2001. (May 15, 2008)http://www.seaworld.org/just-for-teachers/lsa/i-012/pdf/background.pdf
FAQ
1. What is the typical diet of a shark?
Most sharks are carnivorous and feed on a variety of marine animals, including fish, squid, octopus, mollusks, crustaceans, and other sharks. The diet of a particular shark species depends on its physical characteristics, habitat, and behavior. For example, tiger sharks are known to eat sea turtles, while great white sharks feed on seals and sea lions.
2. Are there any vegetarian sharks?
No, there are no known vegetarian sharks. Unlike some marine mammals, such as manatees and dugongs, sharks lack the specialized digestive system needed to break down plant matter. Sharks are obligate carnivores, meaning that they require a diet of animal flesh to survive and thrive.
3. Do sharks ever eat humans?
While shark attacks on humans are rare, they do occur. Most shark attacks are a case of mistaken identity, where the shark mistakes the human for its natural prey, such as a seal or fish. In general, sharks are not interested in eating humans and will usually release the person after the first bite. Fatal attacks are extremely rare, with only a handful of deaths occurring each year worldwide.
4. How much do sharks eat in a day?
The amount of food a shark eats in a day depends on its size and species. Larger sharks, such as great whites and tiger sharks, can consume up to 90 pounds of food in a single meal. Smaller sharks, such as blacktip and hammerhead sharks, typically eat between 1% and 3% of their body weight per day. Some species of sharks, such as the cookiecutter shark, feed infrequently and may go several weeks between meals.
5. Are sharks at the top of the food chain?
Yes, sharks are typically considered to be at the top of the marine food chain. As apex predators, they play a critical role in regulating the populations of their prey species. Without sharks, the marine ecosystem would be thrown out of balance, with potentially devastating consequences for other marine life and the environment as a whole.
Leave a Reply