Do Clownfish Eat Copepods?

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If you have a reef tank, you have a variety of problems to worry about. These include setting up the ecosystem properly, ensuring adequate water quality for the corals and other tank inhabitants, and, my favorite, dealing with benthic algae.

The notion of ‘benthic’ describes organisms that populate the bottom of the ecosystem, covering hard surfaces like rocks or, in your case, the reef.

Benthic algae can be extremely difficult to counter, which is where copepods come in. These small swimming creatures, often only several millimeters large, resemble a flee.

They’re hardly visible with the naked eye because they are tiny and transparent, but you’ll notice their presence once they breed sufficiently.

These herbivorous organisms are great at consuming benthic algae, which is why almost all marine aquarists willingly introduce them to their reef ecosystem.

But what happens when copepods breed out of control and flood the tank? I present to you the solution: the all-popular clownfish.

Benefits of Copepods for Clownfish

Contrary to what some aquarists believe, copepods are not only safe for fish but actually beneficial too.

Some of the most noticeable benefits associated with copepods include:

  • Improved tank hygiene – Copepods are voracious herbivorous organisms that feed exclusively on algae matter. They are your best allies in your fight against benthic algae, which are so prevalent in marine tanks. Sustained copepod activity keeps the tank cleaner and preserves water quality in the long run. This will ensure a healthier and more stable environment for your clownfish to enjoy.
  • Good nutrition – Copepods may not form a complete meal by themselves, but you can’t deny their valuable nutritious content. Clownfish enjoy them quite thoroughly, as they provide them with an easy-to-access food source.
  • Cater to clownfish’s hunting behaviorClownfish are intelligent animals that require a diverse habitat and as much entertainment as possible. The presence of copepods in their environment will keep them busy and entertained as they hunt them down relentlessly. This makes copepods very beneficial to your fish’s mental health.

Plus, copepods provide your clownfish with extra nutrients, boosting their colors and accelerating their growth rate.

Can Clownfish Only Eat Copepods?

Clownfish can eat only copepods, but I wouldn’t advise testing that. Copepods may be nutritious but cannot replace a well-balanced meal plan.

Clownfish don’t rely on copepods alone in the wild either and won’t start in captivity.

You should provide your clownfish with a balanced omnivorous diet that includes insects, worms, algae wafers, fish eggs, small crustaceans, etc.

These are necessary to provide the clownfish with adequate long-term sustenance.

Are There Any Risks to Feeding Copepods to Clownfish?

No, there are no risks linked directly to copepod consumption for fish. These organisms are simply extra sustenance for fish, and many fish species have evolved to hunt copepods specifically.

Clownfish also fall into that category in some sense.

The only danger that I can identify relates to feeding your fish copepods exclusively. This can lead to nutritional deficiencies, given that copepods aren’t exactly well-rounded in terms of nutrient content.

Other than that, copepods are completely safe for your clownfish.

Will Copepods Survive in a Clownfish Tank?

This is a tricky question, with the answer depending on a variety of factors. Generally speaking, yes, copepods will survive in a clownfish tank, but it depends.

It depends on the number of copepods, the number of clownfish, and whether there are other copepod-eaters present in the environment.

Generally speaking, copepods are hardy and adaptable animals, and they breed fast. So, you’re more likely to face a copepod invasion than a copepod apocalypse.

This being said, clownfish are large and strong and showcase quite the appetite for that nutritious copepod meat.

A voracious pair of clownfish can quickly depopulate an entire tank of copepods, giving the benthic algae room to grow and invade the habitat.

So, you need to balance the ecosystem to make sure that your copepods don’t become extinct.

In this sense, consider the following:

  • Watch the fish-per-gallon ratio – Don’t overstock your clownfish. Clownfish grow up to 4 inches, although most specimens will remain smaller and require at least 20 gallons to thrive. Add an extra 10-15 gallons for each additional clownfish you throw into the mix. A 30-gallon tank should be enough to accommodate both the clownfish and the thriving population of copepods.
  • Feed your clownfish properly – Hungry clownfish are more likely to rely on copepods to satisfy their appetite. Feed your clownfish a balanced and optimized diet, and they will only feed copepods occasionally as sport. This will provide the tiny organisms with the space they need to keep their population alive.
  • Don’t add any more copepod eaters – If your copepod population is stable and clownfish do a good-enough job to control it, stick to that winning formula. Don’t add any other copepod killers if you care about your copepod population.
  • Support your copepods – Yes, you can actually support your copepod population by providing them with adequate sustenance. There are a variety of copepod foods available online to use in this sense. Also, you can purchase more adult copepods or even planktonic copepod larvae to restore the copepod population in case it dwindles.

Copepods can seem threatening to more inexperienced aquarists, given that the sight of floating tiny animals in the water is never welcoming.

However, you will soon learn to overcome your initial instinct because it’s actually wrong in this particular case.

Copepods are beneficial to any marine setup thanks to their algae-eating capabilities. With their help, the reef tank will remain cleaner and healthier for your fish to enjoy.

Naturally, you don’t want your copepod population to grow out of control, in which case the clownfish is a welcoming addition to the habitat.


As you can see, clownfish and copepods have a very well-balanced symbiotic relationship, as neither can live harmoniously without the other.

Copepods will provide clownfish with adequate nutrition, great hunting opportunities, and a clean habitat.

On the other hand, clownfish will keep the copepod population fresh by preventing a copepod invasion which will flood the environment with many dead organisms.

It’s a win-win, and you also get to be a part of it.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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