How Do Jellyfish Eat? + What Do They Eat?

Have you ever wondered how jellyfish eat and digest their food? They have no brain, no bones and only one body opening, yet they are effective predators.

How do jellyfish eat? Jellyfish mostly drift and catch whatever touches their tentacles. Tiny stinging cells stun or paralyze the prey. Then the tentacles or oral arms move the food to a single opening that works as both mouth and anus.

Below, we go step by step through how jellyfish catch, eat and digest their food, and what they eat.

Related Article:****How do snails eat?

Broad Answer About How Jellyfish Eat

Let's take a closer look at how jellyfish eat.

Most jellyfish don't chase their food. They drift with ocean currents and pulse their bells to move and stay up in the water. Prey that bumps into the tentacles gets caught.

Let us check it in more detail.

Jellyfish Will Use Their Tentacles To Catch Food

Jellyfish catch food with their tentacles. In some species, such as the lion's mane jellyfish, the tentacles are reported to stretch more than 100 feet.

The tentacles are covered in tiny stinging cells. According to National Geographic Kids, these cells "stun or paralyze their prey before they eat them."

Each stinging cell holds a coiled, thread-like tube that fires into the prey when touched. All jellyfish have these stinging cells, not just the big ones.

Jellyfish Will Put The Food Inside Their Mouth

In many jellyfish, frilly oral arms near the mouth take the food from the tentacles and pass it to the mouth.

The oral arms are usually shorter than the tentacles. The mouth is on the underside, in the center of the bell, and leads to the jellyfish's gut.

Jellyfish move mainly by pulsing their bell. As National Geographic Kids explains, squirting water out of the bell's opening pushes them forward.

Jellyfish Will Digest Their Food

Once the food is inside, the jellyfish digests it in its gastrovascular cavity, a simple gut.

Enzymes break the food down, and cells lining the cavity absorb the nutrients. Like anemones and corals, jellyfish have this one simple gut instead of a stomach and intestines.

Do Jellyfish Have Anus?

No. Jellyfish have only one opening. They take in food and get rid of waste through the same opening, which works as both mouth and anus.

Jellyfish Is In A Hurry

Jellyfish digest their food quickly. National Geographic Kids notes they "wouldn't be able to float if they had to carry a large, undigested meal around."

What Are The Foods Jellyfish Love To Eat?

What a jellyfish eats depends largely on its size and species.

Let us start with the small jellyfish.

Small Jellyfish

Jellyfish are carnivores, though some also take in tiny plantlike plankton. Small jellyfish usually eat:

• Zooplankton, such as tiny crustaceans
• Larvae of fish, crabs and other animals
• Tiny fish
• Tiny plants (phytoplankton)
• Fish eggs
• Other small drifting animals

Large numbers of jellyfish can eat many fish eggs and larvae, which can affect local fish populations.

Jellyfish have no brain. They have a simple nerve net instead, so they react to touch and other signals rather than hunt like fish do. Huge gatherings of jellyfish are called blooms, and they can clog fishing nets and cause problems for fishermen.

Now let us check what the big jellies eat!

Big Jellyfish

Larger jellyfish can catch bigger prey, such as small fish and shrimp. Their stinging tentacles stun prey that touch them, and then the jellyfish moves it to its mouth.

Foods that larger jellyfish eat include:

• Shrimp and other small crustaceans
• Crab larvae and small crabs
• Fish
• Plankton
• Fish eggs
• Other jellyfish

Yes, some jellyfish eat other jellyfish. They don't choose food the way animals with brains do; they eat what their tentacles catch.

Who Are The Predators Of Jellyfish?

Jellyfish are predators, but they're also prey for animals such as:

• Sea turtles, especially leatherbacks
• Ocean sunfish
• Spadefish
• Some tunas
• Other jellyfish
• Some seabirds

Humans also eat jellyfish. It's a common food in parts of Asia, including China, Japan and Thailand, where it's usually salted and dried before being sold.

How Many Jellyfish Species Are There?

There are hundreds of jellyfish species, from tiny ones to giants.

Many are harmless to people, but some are very dangerous. Box jellyfish and some others have stings that can kill a person. Never touch a jellyfish, even one washed up on the beach, since its stinging cells can still fire.

Can Jellyfish Eat A Human?

No. Jellyfish only eat prey small enough for them to handle. But jellyfish stings can be painful and, as National Geographic Kids notes, sometimes very dangerous.

If you're stung, get out of the water and follow lifeguard instructions. Get emergency help for trouble breathing, chest pain or a sting from a box jellyfish.

Final Verdict

Jellyfish mostly drift and let their prey come to them. Stinging cells on their tentacles stun or paralyze the prey, and the tentacles or oral arms move it to the mouth.

They digest food quickly and get rid of waste through the same opening, since they have no anus.

Source: animalhow.com, kids.nationalgeographic.com

Sources

• Jellyfish, National Geographic Kids