American Oceans

What Do Jellyfish Eat?

Jellyfish lurk in the waters of every ocean in the world, so one could expect them to have a varied diet. From shallow bays to the deepest trenches of the ocean, these invertebrates feed on whatever is available in their habitats. 

There are around 2000 known species of jellyfish on the planet. Regardless of species, they tend to be carnivorous–meaning they feed on other animals. However, jellyfish will occasionally consume plant matter as well. 

So, what do jellyfish eat? Here are the main components of the average jellyfish diet. 

The Jellyfish Diet

Plankton 

Plankton–zooplankton in particular– make up the majority of a jellyfish’s diet. They live everywhere there is saltwater, so these microscopic organisms are an easy source of nutrients. 

To feed on plankton, a jellyfish simply needs to float near the surface of the ocean; this is where most planktons live, as they require plenty of sunlight to survive. 

As a jellyfish drifts through the water, it captures the surrounding planktons in their stingers with ease. 

Crustaceans 

Some larger jellyfish species may feed on crustaceans. This includes lobsters, crabs, and even shrimp. 

Unlike plankton, however, crustaceans are a bit more difficult for jellyfish to catch. Because of this, they are not a regular food source for jellyfish. 

When a jellyfish does manage to catch a crustacean, it will trap it within its stingers. These stingers will then paralyze their prey. The jellyfish will then swallow the crustacean whole, absorbing nutrients such as protein and omega acids as it digests. 

Plants 

While these creatures are mainly carnivorous, some jellyfish will eat plants while they are young. Seaweed, algae, and phytoplankton are among some of the plant life that jellyfish will consume. 

Plants are a convenient source of nutrients for young jellyfish. They are abundant in nearly all parts of the ocean, and as they drift through the water, they are easy to catch and eat. 

Plants such as seaweed are very nutrient-dense, especially in minerals such as iron or folate. So while jellyfish are mainly carnivores, consuming plant matter during their adolescence can still help their development. 

Small Fish 

Small fish and their eggs are another significant part of the jellyfish diet. They are protein-dense and full of other essential nutrients that help jellyfish grow and thrive. 

Jellyfish will often linger in areas where smaller fish live. If a fish swims into their mass of stingers, the jellyfish will then paralyze them and swallow them whole. 

Jellyfish may also lurk in fish’s dens in search of their eggs. Like small fish, they are a quick and easy source of protein. 

Other Jellyfish 

There are some instances where a jellyfish will consume its own kind. In these cases, it is usually an adult jellyfish eating their offspring, or sometimes a smaller jellyfish of a different species. 

This is not common behavior for these sea creatures, however. Jellyfish have little to no nutritional value, so consuming others is often not worth the effort. In general, jellyfish only partake in cannibalism when other food sources are scarce. 

How Do Jellyfish Collect Food? 

Jellyfish are opportunistic hunters–meaning they do not actively chase down prey but instead prefer to catch whatever is within reach. They collect prey such as plankton by simply floating in the water and catching what they can with their stingers. 

To catch other prey such as fish, crustaceans, or eggs, they lurk in areas where those animals tend to gather. From there, they wait for prey to come near. 

Once the food is within reach, jellyfish rely on their stingers to do the rest. Jellyfish stingers will release venom that they use to trap and paralyze their prey. Once the jellyfish has paralyzed its prey, it is ready to feed. 

How Do Jellyfish Eat? 

After a jellyfish has captured prey, it uses its tentacles to bring the food toward a hole at the base of its body. This hole has multiple functions; they use it to eat, swim and even expel waste after they eat. 

Jellyfish do not have teeth to chew. Instead, they swallow their prey whole. Once the food is in their stomach, enzymes will break down the materials and absorb the nutrients. 

Once they’ve extracted all of the nutrients from their food, the waste exits their body from the same hole. 

Final Thoughts

Jellyfish play an essential role in the ocean’s food chain. They consume a variety of smaller organisms, including microscopic plankton, various crustaceans, and even other jellyfish. 

In turn, jellyfish are a significant part of other sea creatures’ diets. Sunfish and turtles, for instance, often rely on jellyfish as a food source. Some humans even catch jellyfish and serve them in a variety of dishes. 

Overall, jellyfish play an essential role in the ocean’s ecosystem. With their unusual feeding habits and varied diet, they are nothing short of unique creatures. Looking for more fun jellyfish facts? Check out what is considered the deadliest jellyfish right here.

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