What Do Sea Anemones Eat? 7 Foods They Consume

Sea anemones may look like just one species spread throughout the ocean in different hues. But in reality, there are more than 1,100 recorded species of sea anemones. You may notice that sea anemones have similar characteristics as jellyfish and corals, and that is because they are closely related. They all belong to the family Cnidarians, which hosts animals and organisms that possess stinging cells to protect themselves from predators. 

Sea anemones may often be mistaken as plants rather than animals because of their colorful and flower-like facade, but as a matter of fact, sea anemones are actually animals. And like animals, they depend on food in order to survive, which leaves us the question: what do sea anemones eat?

What Do Sea Anemones Eat?

Sea anemones eat a diet that consists of small animals like fish, crabs, and planktons. Yet, for species of bigger sea anemones, they can eat larger animals such as jellyfish and starfish.

Looking at their physical appearance, it might be easy to assume that these flower-looking animals exclusively eat plants. However, sea anemones are actually carnivores, feeding on other animals underwater. Here are some of the sea creatures that typically compose a sea anemone’s primary diet:

• Plankton
• Crabs
• Fish
• Shrimp
• Starfish
• Jellyfish
• Krill

As carnivores, the majority of sea anemone species prefer protein-rich diets. Due to the fact that they reside underwater, the only animals they feed on are small sea creatures such as small fish or plankton.

Sea anemones grow in size in direct proportion to the size of the food they eat. These creatures are capable of growing up to 6.5 feet in diameter. The smaller anemones devour organisms that are nearly microscopic in size, while the larger anemones are known to ingest creatures as large as crabs and jellyfish. The consumption of ants by a number of giant sea anemones has recently been discovered, although they primarily ingest things that are part of their own habitat.

When held captive inside an aquarium, sea anemones are fed chunks of shrimp, fish, and krill.

How Do Sea Anemones Eat?

Sea anemones eat their prey by utilizing their stinging tentacles that when triggered by the slightest touch, will launch nematocyst, a harpoon-like spherical capsule that is only released by members of the same family. Some sea anemones like to gather their food in, but for some species, the prey is captured using their pricking tentacles.

A paralyzing neurotoxin is then injected into the prey and it is pulled towards the mouth using the sea anemone’s tentacles. The toxin also helps to paralyze the prey, disabling its ability to move.

There is a single entrance in the center of a sea anemone’s oral disc, through which it receives food and emits waste. The sea anemone helps itself by grabbing the potential food through its tentacle and pushing it towards its mouth. The stomach of a sea anemone contains acid that disintegrates protein into a liquid that is easier to swallow, and they spit anything that is indigestible back out again.

Do Sea Anemones Eat Clownfish?

While sea anemones eat fish, they do not feed on clownfish. As a matter of fact, these two sea creatures even form a symbiotic relationship, where the clownfish provides the sea anemone with nutrients it needs and the latter provides it back with a home and protection.

It is widely known that sea anemones create symbiotic partnerships with other animals, and their best-known relationship is with clownfish, which reside inside the anemone’s stinging tentacles to keep themselves safe from predators. The clownfish’s waste and any leftovers actually benefit sea anemones, giving off fuel and nutrients that are necessary for a sea anemone’s diet, and providing them with additional nutrition.

In a study published in 1980, it has been suggested that whenever clownfish are around, there come sudden changes and effects on the sea anemone’s behavior, which surprisingly do not affect the latter’s stinging prowess in any way.

Are Clownfish Immune to Sea Anemones’ Tentacles?

Clownfish are immune to the stinging cells of anemones due to a protective mucous layer on their bodies that appear to be three to four times thicker than regular fish, making them the ideal fish for such a relationship with sea anemones.

Who Eats Sea Anemones?

Sea anemones are fed upon by sea turtles, snails, sea slugs, and fish, such as butterfly fish and mosshead sculpins.

Although sea anemones possess stinging tentacles that deter and protect them from predators, they can’t escape the fact that some animals will still feed on them, especially because they are unable to move. Sea anemones generally live attached to rocks on the bottom of the sea, so the farthest move they can make is by gradually gliding on their base. 

Some sea anemones are also capable of migrating quickly in order to escape predators or by disconnecting from their host, catching a current, and reattaching in a different location.

How Do Predators Eat Sea Anemones?

Despite their defense mechanism, there are a number of sea creatures that have their own strategies in feeding on sea anemones. 

A variety of snails and sea slugs feed on anemones, eating both the body and the tentacles, by approaching the anemone numerous times despite getting stung by its tentacles, and then biting on them. Slugs can take a few bites before the sea anemone detaches itself and floats away, but if the sea anemone does not escape, the slug can eat the entire sea anemone.

Several types of fish can also munch on an anemone’s tentacles. At least forty percent of the mosshead sculpin’s diet is composed of sea anemones, and they live off anemones by pecking and biting on the tentacles. Sea anemones can usually escape and survive these kinds of attacks from predators, and the wounds from the bites can also heal overtime.

The photo featured at the top of this post is © Ernie Cooper/Shutterstock.com