Do Clownfish Eat Copepods? Are They a Good Sign?

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As I was cultivating my reef tank, at some point, I noticed the known copepods floating through the water. At first, I was startled and worried that they would harm my clownfish. However, the next question that popped into my mind was whether or not the clownfish would eat the copepods. That was when I began to research the topic extensively. 

Yes, clownfish do eat copepods. Once found abundant in their environment, clownfish are likely to nibble on copepods, earning a significant nutritional value in return. Some circles take advantage of that, to the point where copepods are used as the sole feeding source for clownfish. 

As we move forward in this article, I will show you what other benefits copepods offer to your tank, and what steps you should take to culture them. Also, I will present a few useful techniques to eliminate copepods if those become excessively abundant in your tank.

Also Read: Clownfish Care Guide

Will Clownfish Eat Copepods?

Copepods are small crustaceans the size of a flea. They are highly nutritious, and that makes them attractive to saltwater fish. This automatically makes them a viable source of food for clownfish, which are saltwater creatures. You may find them in most tanks that feature algae and detritus.

So, the consensus is that clownfish can eat copepods. Though, their efficacy as a food source tends to vary with each aquarist. Some fish owners dismiss them. They argue that, even though clownfish can eat them, they are an insufficient meal, incapable of satisfying clownfish because of their small size.

However, others will tell you that their clownfish have a diet that consists primarily of copepods. Ultimately, you have to leave it to your fish to decide whether or not they can survive on copepods.

They are a free and mostly harmless meal. Therefore, you lose nothing by experimenting with them and waiting to see how well they feed your fish. It isn’t that hard to figure out whether or not a clownfish is hungry. If the copepods are just not cutting it, the clownfish will let you know. 

But if your clownfish develop a taste for copepods, you should celebrate the development because the organisms will solve your tank’s food issues. For many aquarists, copepods and amphipods are superior to flakes and pellets. They have the nutritional content required to keep clownfish sated. But again, it is an issue of experimentation.

Can Clownfish Rely Solely on Copepods?

As mentioned earlier, there are situations in which your clownfish may rely solely on copepods. However, identifying that case could pose a challenge. That is because fish cannot tell you if they are full, nor do they show any distinctive behavior. 

Still, there are a few clues you can look at. If you’ve noticed your clownfish nibble on the copepods in your tank, try adding a few pellets. Then, observe the new eating habits of your clownfish. If they tend to spit out the flakes frequently, that could indicate the copepods are sufficing. 

You should also look for clues in your aquarium. When you are feeding your clownfish too much food, debris will begin to accumulate. You will notice that your filter becomes dirty and that there are vast amounts of sunk food at the bottom of the tank.

If you’ve just introduced copepods to your reef tank, I highly suggest that you wouldn’t cut off the other sources of food abruptly. Conduct gradual changes and allow your clownfish to acclimate. Only when you see the fish show no real interest in your diet, you could try cutting it off entirely. 

If you feel uncomfortable regarding that topic, I highly recommend that you read an article I’ve written on how often clownfish eat and how much.

That guide covers all the necessary principles to ensure your fish remains satiated and healthy. You may also be surprised to know that you can feed your clownfish seaweed and Nori, as I explained in this article.  

  • As you can see in the following video, copepods may reproduce pretty quickly in your aquarium. If they are that abundant in your tank, clownfish will probably rely on those as the primary source of food:

What Other Benefits Do Copepods Offer?

If you have copepods in your tank and you want them gone, species like the mandarin fish eat them as their primary food source. Therefore, you don’t have to work that hard to rid yourself of them. But you shouldn’t be so quick to eliminate them, not when they have additional benefits to offer, for instance:[1]

1. A Food Source for a Variety of Creatures

As was mentioned above, mandarin fish rely on copepods as a food source, and they are not the only ones. Plenty of saltwater creatures will dig through the substrate to find these organisms, including shrimp, crabs, and corals. 

Admittedly, many of the creatures that feed on copepods are challenging to keep. But if you have any of them in your tank and you are struggling to keep them fed, a thriving population of copepods may solve all your problems. 

Sometimes, this can include clownfish. Some clownfish are very picky eaters. If you have a batch that has rejected flakes and pellets, add some copepods to their tank. They will probably chase, catch, and eat the organisms. 

2. Hygiene Maintenance

Copepods will eat the algae and decaying food they encounter in the water. This will allow you to keep your tank clean. You will also find that it doesn’t require quite as much effort to maintain a copepod tank clean.

By eliminating debris, copepods will also lower the ammonia and nitrate concentrations. That will benefit your clownfish, anemones, and generally all reef tank organisms. By maintaining stable levels of solutes and pH, your clownfish are likely to live much longer. 

3. Instinct Stimulation

As was mentioned above, your clownfish will hunt the copepods they find in their tank. This will allow them to tap into the predatory aspect of their instinct that they rarely exercise in the aquarium. The act of hunting the copepods will keep your clownfish healthy. 

That isn’t just true for clownfish. Copepods will generally impact all living creatures in your aquarium, including your anemone. They will bring the artificial environment of a fish tank closer to the natural habitat your fish are wired to. 

4. Colors Enhancement

Copepods are highly nutritious. They do not stop at augmenting the health of fish. They also promote vibrant colors. They can also do this for corals. If you feel like the colors in your clownfish tank are not quite as alluring as you once thought, a diet of copepods could add new life to its aesthetic value. 

That is a comprehensive rule of thumb you should implement in your tank. When the food you provide is diversified, your aquarium will appear alive and intense. If you’ve noticed that the colors of your anemone, corals, or fish have faded, perhaps you should make a few changes in nutrition. 

How to Culture Copepods for a Clownfish Tank

For those of you who actually want copepods in your tanks, you have the option of buying them. However, it might be more rewarding to raise them yourself:[2]

  • Start by getting yourself a container. Any 10-gallon bucket will do. That should be enough. Though, if you can afford a proper aquarium, you might as well get one. 
  • Find a suitable location to position the container. Keep it away from places that expose it to direct heat or cold. Copepods will not respond positively to extreme temperatures.
  • Add an airstone to the container, one that provides medium airflow. You can also use a proper air pump if you have an aquarium. The objective is to provide gentle aeration that will keep the copepods happy and healthy. 
  • Where the salinity is concerned, you should aim for a range of 25-35 ppt. It should match the salinity of the tank that houses your clownfish. This will prevent the copepods from going into shock when you first introduce them to the main tank.
  • Get some delicate plant life (phytoplankton) to feed your copepods. Phytoplankton is quite accessible. You can buy it from a variety of fish stores. The phytoplankton is added to the water in drops. Keep adding until the water turns green.
  • Once everything is in place, you can add some copepods to the container. When you first get the copepods, don’t just throw them in. Give them a moment to reach room temperature. Once you add them to the container, you can sit back and wait for the harvest. Give them a week to multiply.

When it comes to feeding the copepods to your clownfish, use a 100-micron screen. Pour a cup of water from the copepod container through it. The filter will catch the adult copepods. The young ones will fall back into their tank.[3]

If you fail to culture copepods successfully, don’t let it bother you. These things fail all the time and for reasons that are never easy to identify. Just start over. Keep trying until you successfully cultivate a batch of copepods or until you identify the problem.

In the meantime, if you have clownfish that eat copepods, you can buy enough to keep them sated until you harvest your own. That is where I highly recommend the 5280 Pods bundle (link to Marine Depot). That fantastic mix consists of Tiger, Tisbe, and Apocyclops copepods that are highly nutritious and amazingly beneficial. 

How do You Eliminate Copepods?

Copepods are harmless, and their presence in your tank should not worry you. That being said, some people do not like them. They can become a source of irritation for the fish in your aquarium, especially if they grow to such large numbers that they begin crawling incessantly across the bodies of your fish.

The behavior of your fish will tell you that they have had enough. If they keep shuddering, you can conclude that they are not that amused with the tinkling sensation the presence of the copepods produces.

If you realize that your clownfish are exhausted because they cannot shake the copepods, no one will blame you for taking steps to remove them from the tank.

If you don’t have one, introduce a species that eats copepods. This will either eliminate them or reduce their population to a manageable number. If you don’t want new fish in your tank, you may also buy a canister filter (hang-on type) with the finest micron sleeve you can find. It will filter out the pods.

However, keep in mind that the filter is the permanent solution. The copepod-eating fish is the natural alternative. Use a method that suits your tastes and fits your situation. Either way, the number of copepods should decrease significantly. 

What Else do You Need to Know About Copepods?

Some people will tell you that copepods are entirely harmless. However, that isn’t entirely true. There are so many species of copepods, roughly 11,500.[4] And those are just the species that have been discovered thus far.

Of these known species, one-third are parasitic, and these could pose a threat to clownfish. If you want to know how copepods fit into the community you have created in your reef tank, you need first to understand the creatures:

1. What do Copepods Look Like?

Copepods are quite small. You might have seen them in your tank without knowing it. They are tiny white bugs measuring roughly 1 to 2 mm.[5] They look a lot like shrimp if you investigate them carefully, consisting of a cephalothorax and abdomen, not to mention ten legs.

From a distance, they are just specks of dust. Closely related to crayfish and water fleas, they are free swimmers during their larva and juvenile stages. However, as adults, they prefer to occupy the substrate. 

2. Where do Copepods Come From?

You can find copepods in a variety of settings. They are not restricted to saltwater; you may be surprised to know that freshwater aquariums have them as well. Copepods can dwell in lakes, rivers, streams, ocean sediment layers, etc. 

Some live in the foliage in shallow water. Others prefer to stay at the bottom.[6] In an aquarium, they can exist in the hundreds or thousands, depending on the environment. They are likely to adjust to your current tank settings.

3. What Are Copepods?

Copepods are part of the Hexanauplia class in the Crustacea subphylum. They have ten orders. Some of them are dominant members of the zooplankton, which, in turn, make up Plankton.[7] They have a taste for algae, diatoms, and the like.

They have a relatively straightforward role in water. They eat tiny plants, and other more massive creatures eat them. The latter fact isn’t an issue because they are pretty abundant in the wild. Besides plant life, they can consume bacteria, rotifers, tiny insect larvae, and various organisms small enough for them to eat. 

Of the parasitic and carnivorous copepod species in the world, few are found in saltwater aquariums. Most copepods are just another source of food in domestic tanks. 


Yes, clownfish are likely to consume copepods if presented in their tank. You are even advised to enforce that yourself since copepods offer a high nutritional value to fish and their environment. 

However, keep in mind that they reproduce pretty quickly and, in high numbers, may pose an issue. If that happens, you may use a canister filter with a delicate micro-sleeve. You could also add a few fish that rely on copepods to fight the pandemic, such as the mandarin fish.

I hope my article has answered your question of whether or not clownfish eat copepods. If you have any questions or insights, feel free to contact me in person. I will do my best to get back to you as soon as I can.