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Cory Catfish Swim Bladder Issues (Signs, Causes, & Treatment)

Cory Catfish Swim Bladder Issues (Signs, Causes, & Treatment)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Seeing your cory catfish struggle to swim around normally will be worrisome. Are you seeing that the fish is swimming upside down or sideways?

Perhaps the fish is even swimming in circles. This is a likely sign that the cory catfish is experiencing some type of swim bladder issue.

If you’re new to caring for fish, then you might not know a lot about swim bladder problems. Many types of fish have swim bladders, and malfunctions can make it hard for the fish to swim normally.

Read on to learn about cory catfish and swim bladder issues. This will ensure that you understand how you can best help the fish.

What is a Swim Bladder?

Swim Bladder of a Carp on a Table

If you don’t yet understand what a swim bladder is, then you’ll need to know that it’s an organ that many fish possess. A swim bladder is a gas-filled sac that helps fish to control buoyancy in the water.

The sac fills up with gas and deflates when necessary. Without the swim bladder, many fish wouldn’t be able to control how they swim normally.

It allows them to stay upright while swimming and ensures that they have fine control over their movements. When the swim bladder malfunctions, it’s going to prevent the fish from being able to swim as it should.

You might see a cory catfish swimming in circles or swimming completely upside down. Some fish can get around a little bit when they have swim bladder issues, but others will barely move.

It’s even possible that you might see the cory catfish laying on its side since it isn’t able to move normally. You’ll definitely want to try to fix swim bladder problems so that the fish can get back to normal.

When swim bladder issues go unaddressed, the fish might wind up dying. This could happen for several reasons.

A fish that has a malfunctioning swim bladder will be vulnerable. It won’t be able to protect itself from other fish very well.

Also, it can make it very hard for the fish to be able to eat. If the fish can’t get around much at all, then it might wind up starving to death if things go really bad.

Thankfully, the condition is treatable. You’ll learn more about what you’re supposed to do later in the article.

What Causes Swim Bladder Problems?

There are actually several potential causes of swim bladder problems. It could be something minor that you’ll be able to solve rather quickly.

It’s also possible that the malfunctioning swim bladder could be related to a more complicated issue. Below, you’ll get some information that will help you to determine what is going on with your fish.


Goldfish With Swim Bladder Issues Swimming Upside Down in Tank
Goldfish With Swim Bladder Issues Swimming Upside Down in Tank

Fish can have swim bladder problems when they become constipated. If you feed your cory catfish more than you should, then they might wind up getting swollen bellies.

When a fish becomes constipated it’ll lead to it having swelling around its belly. This winds up having a negative impact on the swim bladder.

You see, the swollen belly is going to press against the swim bladder. Since the swim bladder is just a gas-filled sac, the swollen belly will prevent the organ from being able to inflate and deflate normally.

Thus, the fish won’t be able to control its buoyancy as it should. It’ll wind up swimming around in circles or swimming sideways due to having a malfunctioning swim bladder.

This is a fairly simple issue to fix, but you still don’t want to allow your fish to become constipated. It’ll be wise to avoid overfeeding the cory cats in the future.


Infections have the potential to cause swelling in the fish. An infection of the intestinal area can cause inflammation that will lead to swim bladder issues.

Fish can wind up getting infected with many different types of bacteria. Typically, cory cats will only have to worry about getting infected when dealing with water quality issues.

Poor water quality will stress the fish and make them more susceptible to bacterial infections. This can wind up being the direct cause of swim bladder issues.

To protect the fish, be sure to keep a close eye on the water parameters. You should be testing the water regularly using a pH balance testing kit.

Remember that heightened levels of ammonia, nitrates, and nitrites will be dangerous for cory catfish. You must do your best to keep the fish tank clean.

Regular water changes will be necessary to protect the fish as well. You should be doing weekly water changes if you want the water to remain clean.

Another thing to consider is how crowded the tank is. A crowded fish tank will get dirty faster, and this can throw the balance of the water off.

Your fish might get stressed due to being put in a cramped fish tank, too. This makes them more likely to get infected.

To clear up swim bladder issues that are caused by infections, you’ll need to get rid of the infection first. It’ll also be necessary to address the situation in the fish tank or things won’t truly improve for the fish.

How to Fix Swim Bladder Issues

Peas Being Boiled in a Pot of Water

Fixing swim bladder issues will be easy enough once you understand what to do. However, it should be noted that this is a serious problem that shouldn’t be taken lightly.

If your fish is simply constipated, then you’ll need to get rid of the constipation. The easiest way to do this is to feed the fish a boiled pea.

Feeding a cory catfish a boiled pea is going to make it poop a lot. This will clear up the constipation and make it so that the fish will feel normal again.

Fixing problems with an infection will be a bit more complicated, but it can be done. The fish will need to be treated with some type of medicine to clear up the infection.

Then you’ll just need to keep an eye on the fish to ensure that it keeps eating so that it can get better. The swim bladder problem should go away when the inflammation is reduced.

Of course, fixing any problems in the fish tank will also be an important part of the process. Failure to address problems in the tank will just lead to the fish going through the same issue again at some point.

Final Thoughts

A Group of Sterbas Corydoras at the Bottom of a Freshwater Tank

You should feel a lot more informed about what swim bladder issues mean. When a cory catfish is dealing with swim bladder issues, it can be very scary.

If you don’t know what’s going on, you might assume that the fish is dying. This isn’t necessarily the case, but you will want to try to help your fish get better.

It could be that the fish is constipated and needs to be cleared out. In this situation, feeding the fish a boiled pea will be enough to get it back to normal.

Another possibility involves the swim bladder problem being related to an infection. A bacterial infection in the intestinal area can cause swelling that will cause the swim bladder to malfunction.

Clearing up the infection using antibiotics should help to get the fish back to normal. Typically, you’re going to have to address problems with the water quality as well.

Continue to look after the fish and it should get better. Failure to treat the fish could wind up leading to the cory catfish dying.

A fish might starve due to not being able to eat properly. It could also get bullied to death by other fish depending on what other fish happen to be in the tank.

Keep all of this in mind and try to do right by your cory cats. You should be able to get them back to normal.

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