What Do Jellyfish Eat? Understanding Their Food Choice!

Taking care of a jellyfish pet can be an exciting and rewarding experience. However, one of the most crucial aspects of caring for these delicate creatures is ensuring they get the right nutrition.

In this post, I will dive deep into the world of jellyfish food choices, exploring their dietary needs and providing useful tips and recommendations to ensure your jellyfish pet gets the best possible diet.

Before I list their favorite foods, grab a cup of coffee☕️, sit back, and let’s learn more about these exotic pets.

Jellyfish Anatomy and Feeding Mechanisms

Simple Structure of a Jellyfish

The jellyfish is a simple animal with a bell and tentacles. The bell is the large dome-shaped structure at the top of your jellyfish, which contains its organs. Jellyfish tentacles are covered in stinging cells called nematocysts that help them capture prey.

The oral arms are specialized tentacles for feeding and catching food for digestion. They are usually shorter than other tentacles but contain more nematocysts than other body parts.

These structures can be sticky or sharp depending on what type of food you want to catch; some jellies use them like fishing lines!

How Jellyfish Captures their Prey?

The nematocysts are the stinging cells of jellyfish. These cells capture prey and can be triggered by contact with prey. When triggered, they release a coiled thread that propels out of the cell and attaches itself to a nearby organism.

The use of mucus to capture prey is less straightforward than that of nematocysts; however, it still plays an important role in allowing jellyfish to feed on small organisms such as planktonic animals and microalgae. Jellyfish use this substance to trap aquatic organisms by secreting large amounts of mucus into the surrounding water column through specialized pores called ostia (singular: ostium).

Digestion and Nutrient Absorption in JellyFish

The gastrovascular cavity is a central digestive cavity that allows jellyfish to digest food and absorb nutrients.

Jellyfish do not have a stomach, so they do not store food or secrete acid to break down their meals before they absorb them. Instead, they rely on their large central cavity (the gastrovascular cavity) as an organ of digestion and absorption.

The epithelial lining of this cavity contains millions of ciliated cells that push waste products out through pores in its wall; meanwhile, other cells take up dissolved nutrients from the water around them and pass them into their bodies via endocytosis.

Dietary Variations Among Different Jellyfish Species

The diet of a jellyfish varies based on species, size, and habitat. So, I’ll examine the diets of some common species of jellies below –

Jellyfish Diets: Varied by Species, Size, and Habitat

While most jellyfish are carnivorous, a few species are omnivorous or detritivorous. Jellyfish are opportunistic feeders that eat a variety of prey, including zooplankton (microscopic organisms), fish eggs and larvae, crustaceans like shrimp or krill, and other jellies.

They have no means to chew food, so they must digest it quickly to capture another meal before it escapes. Some species have specialized oral arms for catching prey, while others rely on their tentacles to capture prey items that get too close for comfort!

While some jellyfish may be considered harmless grazers because their diet consists primarily of algae or other phytoplankton (free-floating plants), these same animals can also become dangerous predators when feeding on larger animals such as shrimp or fish eggs/larvae – making them both herbivores AND carnivores!

Jellyfish with Their Preferred Diets

Moon jellyfish are a type of cnidarian that feed on plankton. They have been observed to eat copepods, tunicates, and other small crustaceans.

Lion’s mane jellyfish are omnivorous, meaning they eat plant and animal matter. They have been observed consuming zooplankton such as copepods, larval fish, and algae (phytoplankton).

Box jellies are carnivores that feed primarily on smaller marine organisms like fish eggs and larvae but will also consume small crustacean zooplankton when available in high densities near the surface waters where box jellies often reside.

Jellyfish Species Explained

There are many different species of jellyfish, and each one has its unique diet. Some are carnivorous, others are omnivorous, and others are detritivorous (meaning they feed on dead organic matter).

Carnivorous jellyfish include the Lion’s Mane (Cyanea capillata) and Moon Jellyfish (Aurelia aurita). They eat smaller marine life, such as zooplankton, fish eggs, and larvae.

Omnivorous species consume plant material, such as algae or diatoms, and animals, like copepods or other small crustaceans, live in the water column.

Examples include Warty Comb Jellies (Mnemiopsis leidyi), Green Sea Nettles (Chrysaora hysoscella), and Blue Blubber Jellyfish (Catostylus mosaicus).

Lastly, there is one type of jellyfish called a Sea Wasp, which feeds solely off dead organisms like decomposing fish carcasses instead of living prey like other species do; this makes them detritivores!

Typical Jellyfish Prey

Jellyfish are known for their ability to change colors. Still, they also have one of the most interesting and varied diets of any aquatic animal—jellyfish prey on various animals, including plankton, small fish, crustaceans, and other jellyfish.

Jellyfish can even eat other jellyfish! Jellyfish are opportunistic feeders who take advantage of food sources when they’re available—this means that their diet depends on prey availability at any given time.

Common Jellyfish Prey’

The following are some of the most common types of prey for jellyfish:

  • Plankton is a general term for small organisms that float in water, including bacteria, algae, protozoa, and other tiny creatures.
  • Small fish that swim near or above the surface of the ocean.
  • Crustaceans like shrimp and crabs live on or near the seafloor. Jellyfish can be found in oceans around the world, freshwater lakes, and saltwater seas.

Opportunistic nature of Jellyfish.

Jellyfish are opportunistic feeders, meaning they eat anything they can get their tentacles on. They don’t have a specific diet and are not picky eaters.

Jellyfish will eat anything small enough to fit in their mouth, which ranges from plankton to small fish and crustaceans.

How do Environmental Factors Influence Jellyfish Diets?

Jellyfish are opportunistic feeders and can eat almost anything. For example, the moon jellyfish (Aurelia aurita) is known to consume plankton, small fish, crustaceans, and other jellyfish.

Jellyfish can move from one food source to another when necessary. They have a special structure called a “cnidocyte” that allows them to sting their prey with their tentacles.

These stings cause paralysis in their prey so that jellyfish can consume them easily.

Jellyfish Blooms and Their Impact

The term “jellyfish bloom” refers to an increase in the number of jellyfish at a particular location over time. Many factors, including climate change, overfishing, pollution, and habitat destruction, can cause jellyfish blooms.

Jellyfish blooms can significantly impact marine ecosystems because they compete for food resources with other organisms, such as shellfish and fish larvae. In addition to consuming plankton—tiny animals that live in water bodies—jellyfish eat zooplankton (small crustaceans) and other jellyfish.

Predation is another way these creatures affect each other within their ecosystem; they are predators of other jellyfish species such as the moon and comb jellies.”

Jellyfish bloom and its Causes

A jellyfish bloom is a sudden increase in the number of jellyfish. The causes of these blooms include climate change, overfishing, and pollution.

Eutrophication is also a contributing factor to jellyfish blooms because excess nutrients can cause algal blooms that stimulate the growth of jellies. Jellyfish eat small marine organisms like plankton.

When fewer predators are around to keep their numbers down, they can multiply quickly and become very abundant–a phenomenon known as “jellyfication.”

Impact of Jellyfish Blooms on Marine Ecosystems

The impact of jellyfish blooms on marine ecosystems is significant. First, it’s important to note that jellyfish are not a food source for other organisms. They do not serve as prey for fish or other marine wildlife that depend on plankton for survival (i.e., zooplankton).

Instead, jellyfish prey directly upon zooplankton—which could be considered their main competition in the food web–and compete with them over resources such as light and space within their environment.

Potential Solutions to Mitigate the Impact of Jellyfish Blooms

To mitigate the impact of jellyfish blooms on the marine food web, you must reduce overfishing and other human activities that threaten ecosystems.

In addition, you must address climate change by reducing carbon emissions, preserving habitats, and protecting critical species like coral reefs. You also need to reduce ocean pollution and increase research into how acidification will affect marine life.

What Do Jellyfish Eat? List of 10 Favorite Foods

Here’s a list of 10 foods, Jellyfish love to eat –


Zooplankton is tiny ocean animals that float in the water. They are the most important food source for many sea creatures, including copepods, krill, and jellyfish. Jellyfish eat zooplankton by capturing it with their tentacles and pulling it into their mouths.

Jellyfish can’t see well, so they must rely on other senses to find food. Their sense of smell helps them detect prey like zooplankton floating nearby but not always within their tentacles’ reach.

Hence, some species use bioluminescence (light produced by living organisms) to attract prey to them instead!

Fish larvae

Jellyfish are carnivores who eat anything they can get their tentacles around, including fish larvae and eggs.

They’ll also eat crustaceans like shrimp and crabs if they have the chance to catch them in their stinging net (which isn’t hard when you’re as big as a car).


Copepods are the most common zooplankton, and they feed on phytoplankton. They’re tiny crustaceans living in open water, like the ocean or sea. Copepods are a crustacean (like shrimp) found in all aquatic habitats, including lakes and rivers.

The word “copepod” comes from Greek words meaning “to crawl” and “foot.” This refers to how these animals move around by wiggling their bodies instead of swimming like other marine animals do–they don’t have fins!


Phytoplankton is tiny plants that float in the ocean. They’re the base of the ocean food chain and a major food source for many animals.

Phytoplankton includes diatoms, dinoflagellates, coccolithophores, and other algae. They live in all oceans of the world but are most abundant near coastlines where they can get enough light to photosynthesize (make their food).

Phytoplankton also uses nutrients from bottom sediments as fertilizer for growth; these nutrients are released when dead organisms sink through water layers and decompose at deeper levels where there is less oxygen available than at surface levels where phytoplankton live.

Small fish

Jellyfish eat small fish. They also eat fish eggs and larvae, so they’re not picky!

If you have ever seen a jellyfish in the wild, chances are good that it was eating something at the time.

The last thing you want to do is get close enough for your picture but not far enough away that your friend doesn’t get eaten by one of these fearsome predators.

Fish eggs

You might be surprised to learn that jellyfish are partial to fish eggs. These tiny eggs are easy to catch, making them a favorite food for some species of jellyfish.

They’re high in protein, fats, vitamins, minerals, and carbohydrates, making them perfect for your next meal!

Small crustaceans

The jellyfish is a sea creature that eats small crustaceans. A crustacean is an aquatic arthropod with a segmented exoskeleton and several pairs of jointed legs used for walking. They are also called shrimp, lobsters, and crabs.

Jellyfish eat small crustaceans to survive on land or in the ocean water because they don’t have any other food source except for this type of animal living organism.


Tunicates are also called sea squirts, and they’re filter feeders. That means that tunicates eat plankton, a very tiny sea animal.

They have an internal structure called a lophophore that looks like it has little tentacles sticking out from the top of their body.

The lophophore helps them catch their food by filtering it through mucus-covered holes in their bodies—just like you would use a net or strainer to catch food!

If you see one on your next beach vacation, don’t worry: They aren’t dangerous, just cute creatures who enjoy eating plankton!

Other jellyfish

Jellyfish are carnivores, meaning they eat other animals. The vast majority of them eat other jellyfish and small crustaceans. Some species also feed on plankton–tiny organisms that float in the water column.

While it’s not common for a jellyfish to consume fish eggs, there have been instances where this has happened.

One species (the Irukandji) is known for its ability to kill people via stings from its tentacles. They live in Australia’s Great Barrier Reef and can grow up to 12 inches long!


Ctenophores are a very diverse group of animals. They are not jellyfish but belong to the phylum Cnidaria and can be found in tropical and temperate waters.

Ctenophores have tentacles with rows of stinging cells that they use to catch prey or defend themselves against predators (such as fish).


So, what do jellyfish eat? Well, it’s not just one thing. Jellyfish are very diverse creatures, and they can eat various things.

Some species prefer to eat zooplankton, while others prefer small fish or eggs. Ctenophores are even more specialized in their diets because they mainly eat tunicates!

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