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What do Sharks Eat?

Adam Hill
Adam Hill

There are hundreds of shark species in the world, all of which have slightly different eating habits. An individual description of the diets of each family of sharks would be impossible, but there are some general consistencies throughout. For instance, all sharks eat meat to some degree. Sharks are to the oceans what lions are to the African plains, meaning that they are at the top of their respective food chain. They often weed out the sick and weak animals and contribute to the "survival of the fittest" in their realms. Perhaps ironically, the largest of all sharks, known as the whale shark, feeds almost exclusively on small fish and plankton.

Popular culture has tended to cast sharks in the role of dangerous, belligerent animals who attack humans at the slightest provocation. While it is true that some species of sharks go after large prey, like seals and other sea mammals, they only threaten humans when they feel threatened themselves. Most sharks eat a little bit of everything that they can find in their local area. This is not just because that is the most convenient option, but also because sharks usually only eat once every two to three days, and when they do eat, it can be as much as three percent of their total body weight. Almost everything in the sea is eaten by some type of shark.

Great white sharks usually attack their prey from below.
Great white sharks usually attack their prey from below.

The types of food that generally appeal to the most sharks are things like squid, mid-sized fish, and some types of crustaceans. Some sharks have been known to swallow non-food items that make their way into the oceans from land, such as license plates and other man-made objects. Tiger sharks are the best example of this type of eating. These sharks eat basically anything in their path, including large sea birds and turtles, and have developed a reputation of being opportunistic and greedy eaters because of this.

Many sharks feed on squid.
Many sharks feed on squid.

To make possible the wide variation of things that sharks eat, they have evolved many different feeding mechanisms. In species that consume primarily meat, many rows of sharp teeth rip and tear their food, and are constantly being replaced as they fall out. Sharks do not chew well, however, and proper digestion can take some time. This is one reason why their meals are as infrequent as they are. Some species of sharks eat primarily plankton and smaller marine life, and so their jaw structure is more loosely attached and oddly shaped, to enable them to vacuum up their prey from the sea floor, or obtain food in other unusual ways.

Frequently Asked Questions

What is the primary diet of most shark species?

Tiger sharks often eat sea birds.
Tiger sharks often eat sea birds.

Most sharks are carnivorous and primarily feed on other marine animals. Their diet can include fish, crustaceans, mollusks, plankton, and even other sharks. Larger species, like the great white shark, may also hunt marine mammals such as seals, sea lions, and occasionally small whales. The specific diet varies by species, habitat, and available prey.

Do any sharks eat plants or algae?

Some sharks pursue large prey like seals.
Some sharks pursue large prey like seals.

Sharks are predominantly carnivores, and there are no known species that eat plants or algae as a primary food source. Their digestive systems are not designed to process plant material efficiently. However, some shark species may inadvertently consume small amounts of algae or seagrass while hunting for prey.

How do filter-feeding sharks like whale sharks and basking sharks find their food?

A tiger shark will eat anything in its path, including non-food items.
A tiger shark will eat anything in its path, including non-food items.

Filter-feeding sharks, such as whale sharks and basking sharks, feed by swimming with their mouths open to capture plankton, small fish, and other tiny organisms in the water. They have specialized gill rakers that trap these small particles as water passes through their gills. According to research, whale sharks can filter over 600,000 liters of water an hour to extract their food.

Can sharks adjust their diet based on the availability of prey?

Yes, sharks are opportunistic feeders and can adjust their diet based on prey availability. They are known to be highly adaptable, often switching to different prey species when their preferred food sources are scarce. This adaptability helps them survive in various marine environments and contributes to their success as apex predators.

Do sharks ever eat non-living food or carrion?

Sharks are not averse to scavenging and will consume carrion if the opportunity arises. This behavior is more common in species like the tiger shark, which is known for its less discerning palate. Eating carrion allows sharks to take advantage of all available food resources in their environment, ensuring they get the necessary energy for survival.

How does the diet of a shark influence its behavior and habitat?

The diet of a shark greatly influences its behavior, habitat, and even physical adaptations. For instance, sharks that feed on hard-shelled prey like crabs and mollusks have strong, flat teeth for crushing, while those that hunt fish or marine mammals have sharp, pointed teeth for gripping. Their hunting strategies and chosen habitats are often closely aligned with the type of prey available, affecting their migration patterns and social behavior.

Discussion Comments

RoyalSpyder

Considering how nearly everything in the sea is eaten by some type of shark, does that mean that aside from whales, no sea creature is safe in the ocean? That's a great example of how dangerous sharks are. They are a literal force of nature, and they're the scourge of the seas.

Funny though, until reading this article, I never realized that the media exaggerates how threatening sharks can be, and I'm surprised that they only attack when provoked. However, though this may be true to an extent, it's always a good idea to be cautious regardless. After all, we (humans) may be at the top of our respective food chain, but sharks are still at the top of theirs, whether we go for a swim or not.

Viranty

@Chmander - Probably not, but they might have to watch out for whales. They can be very intimidating, and unlike sharks, which are relatively small, whales have their huge size that matches their power. Aside from that, I don't think sharks have any threats in the ocean.

Chmander
I like how it's mentioned that sharks are at the top of the food chain. I shows how powerful they really are. However, regardless, it makes me wonder, do they *ever* get attacked or eaten by sea creatures? I highly doubt it, but I'd still like to know.

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    • Great white sharks usually attack their prey from below.
      By: Uryadnikov Sergey
      Great white sharks usually attack their prey from below.
    • Many sharks feed on squid.
      Many sharks feed on squid.
    • Tiger sharks often eat sea birds.
      By: Stefan Krasowski
      Tiger sharks often eat sea birds.
    • Some sharks pursue large prey like seals.
      By: Erni
      Some sharks pursue large prey like seals.
    • A tiger shark will eat anything in its path, including non-food items.
      By: Ian Scott
      A tiger shark will eat anything in its path, including non-food items.