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Why Your Clownfish Is Swimming Vertically!

The popularity of keeping clownfish continues to grow with each year that passes with many people new to keeping saltwater fish choosing a clownfish as one of their first additions to their tank.

This usually results in a number of questions from the community asking about how they should be taking care of their clownfish as well as asking about various types of behavior that they see in their clownfish.

Each month we see some people reaching out and asking about their clownfish swimming vertically so we have decided to publish our own dedicated article on the topic.

Our hope is that we will be able to help as many of our readers as possible who have a clownfish that is swimming vertically as well as help you better identify the reason that your clownfish may be swimming in this way.

Now, we often see people worrying that their clownfish may be having issues with swim bladder disease or something similar if it starts to swim vertically.

Although this is a possibility, it is usually not the case and most of the time when a clownfish decides to swim vertically it is by the choice of the clownfish and it is just due to one of their quirks and there is nothing actually wrong with the fish.

Is It Normal For A Clownfish To Swim Vertically?

Although it is not normal for a clownfish to swim vertically, some clownfish will choose to swim vertically at times due to a number of reasons with it usually being their own choice and not due to any problem such as swim bladder disease.

Although it is peculiar to see, clownfish do have a number of quirks in the way that they behave and this is just one of them.

One way you are able to rule out swim bladder disease as the potential cause is to watch how your clownfish swims in its tank and see if it is able to freely switch from swimming vertically to swimming horizontally or not.

You will often find that the clownfish is able to switch between the two types of swimming at will without issue and this rules out swim bladder disease.

Just keep in mind that if the clownfish is swimming vertically due to it “hosting” a specific area of your tank then it may be a while before the clownfish decided to swim horizontally again.

If your clownfish is swimming vertically due to swim bladder disease then over the coming days it may end up rotating all the way over to swimming upside down giving you another indication of the cause.

Why Is My Clownfish Swimming Vertically?

The vast majority of clownfish will find an object in their tank be it a decoration, an anenome or coral to “host” and take as their territory.

It can be relatively common for some clownfish to swim vertically when hosting, especially when they have only just settled on their host object as they usually feel protective of it and will stay as close to it as possible and sometimes, swimming vertically allows them to stay closer than swimming horizontally.

Although rarer, other reasons that your clownfish may be swimming vertically include the water flow in your tank being incorrect but our article going over clownfish water flow should be able to help with that.

Clownfish tend to be more aggressive than other people initially think and we have an article on clownfish aggression too. If a clownfish is constantly being nipped or chased by other clownfish in your tank or other fish species, its stress and anxiety levels will skyrocket and it may swim vertically too.

It is usually easy to diagnose both of these causes of clownfish swimming vertically in their tanks though.

You can just check your water flow settings and keep and eye on how the other fish in the tank interacts with the clownfish that is swimming vertically.

If you do notice that your other clownfish are constantly nipping the clownfish then our article on how to stop two clownfish from fighting may be worth reading.

Should I Be Worried If My Clownfish Is Swimming Vertically?

For the most part, there is generally no need to worry if your clownfish is swimming vertically as the more common causes are easy to identify and easy to fix without a serious risk being present.

If your clownfish does slowly rotate over to swimming upside down then there is a good chance of your fish having swim bladder disease though and it will need to be treat.

Due to there being a number of potential causes of swim bladder disease, booking a short video call with a veterinarian is probably the best route to take.

They will go over your clownfish via video call and assess its behavior while asking you a few questions before offering you advice on how you should move forward.

If the cause of the swim bladder disease is a bacterial infection then the vet will usually issue a broad-spectrum antibiotic to help treat the fish with this treatment usually having a high success rate.

Some of the other causes of swim bladder disease can be harder to treat though with some being incurable but a vet will be able to better advice you on that.


That brings our article going over why your clownfish is swimming vertically to an end. We hope that we have been able to help you better understand the various reasons why your clownfish may be swimming vertically as well as how you are able to treat some of the more serious issues. Most of the time when you see a clownfish swimming vertically though, it is simply a part of its hosting behaviour and although it does look strange, it can be totally normal in some situations with there being nothing to worry about and there no need to worry about trying to treat the issue.