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Why Does My Cory Catfish Have a Red Belly?

Why Does My Cory Catfish Have a Red Belly?

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

Cory catfish are great aquarium fish to own. You’ll find that these fish are some of the most peaceful community tank members.

It’s very likely that you want to do your best to care for these fish to keep them around. Generally, cory catfish are considered to be hardy.

However, the fish are susceptible to certain health issues that can be problematic. If you notice that your fish has a red belly, then you’re going to be understandably worried.

What causes a cory catfish to have a red belly? Is this a sign of a serious medical issue?

Keep reading to learn about what causes cory catfish to get a red belly. You’ll also learn about what can be done to help the fish.

Red Blotch Disease

Corydoras with Red

Red blotch disease is a common problem that cory catfish have to deal with. This disease is known to cause fish to have red and bloody sores on their bellies.

The sores on the belly might be clean, but they could also be bloody. Often, you’ll see dead white skin on the sores, and this will make them look like blisters.

You need to take this disease seriously since it has the potential to kill the fish. When fish get red blotch disease, they might show symptoms for weeks and even months.

The infection will continue to spread, and it can wind up causing the fish to die. These bloody sores aren’t going to just appear on the belly either.

It’s normal to see bloody sores show up elsewhere on the body. Your fish can look pretty rough when it is dealing with this condition.

What Causes Red Blotch Disease?

You’ll find that red blotch disease is caused by types of bacteria. It’s believed that the disease is caused by the same bacteria that causes fin rot.

Any fish has the potential to get fin rot, but only bottom-dwelling fish seem to get red blotch disease. It’s thought that the fish spending so much time resting on the substrate leads to them getting red blotch disease.

Of course, there are many things that will make it more likely that the fish will get red blotch disease. For example, poor water quality will play a big role.

If you haven’t been keeping a close eye on the pH balance of the water, then the parameters might be way off. Water that is too basic or too acidic can become a problem for your fish.

Likewise, keeping fish in dirty water or not monitoring the temperature of the water will cause issues. There are many issues that can occur with water quality that will negatively impact your fish.

Significant fluctuations in the pH balance or temperature can cause your fish to enter a state of shock. This will make them more likely to become infected.

Taking good care of the fish tank is imperative when you want to protect your fish. The best thing to do is to try to prevent red blotch disease by making it very unlikely that the fish will contract it.

Do weekly water changes of 15% to keep the water as clean as you can. Use a very good filter and test the tank regularly using a pH balance testing kit.

If you’re being proactive about tank maintenance, then it’ll be far less likely that you will have issues with red blotch disease. Just do your best to be careful.

Use the Right Type of Substrate

Cory Catfish Near Substrate

Using the right type of substrate is important to protect your cory catfish, too. Some people make the mistake of using harsh materials for the substrate that will harm the fish.

You should be using aquarium sand for the substrate since that will be more natural for the fish. If you use something such as gravel, then the fish will be harmed by acting naturally.

Cory catfish spend a lot of time sifting through the substrate looking for food. This is a natural behavior for the fish, and they’re going to keep doing this even if the material isn’t right for it.

When you use gravel as the substrate material, it can cause cory catfish to get abrasions and go through other issues. Sometimes, the fish will damage their whiskers, and this can make them more at risk for getting infections.

Be sure that you’re using appropriate sand as the substrate material for your tank. It’ll protect the cory catfish and ensure that they can live normally.

Can Red Blotch Disease Be Treated?

Yes, it is possible to treat red blotch disease. Treatment is going to involve two factors that need equal consideration.

First, you’re going to need to fix what is causing the fish to be infected by this bacteria. This means resolving issues with poor water quality and fixing the type of substrate that you’re using.

Cleaning up the fish tank and monitoring the water parameters better will be easy enough. Just make an effort to do things the right way for the sake of the fish.

You’ll also need to treat the infection using certain types of medication. Many types of antibiotics are known to help when treating fish for red blotch disease.

One of the most common types of antibiotics that are used to treat this issue is tetracycline. Some use aquarium salt to treat the disease as well, but you need to be very careful not to use too much salt if you go that route.

Spoonful of Salt

Cory catfish can easily suffer and die if you use too much salt in the tank. Just treating the fish with antibiotics should be enough.

There is the possibility that the fish will have to deal with secondary infections. The medicine should clear everything up over time.

Whether the fish will make a full recovery will depend on various factors. For example, if you catch things early, then it’s more likely that everything will be fine.

It’s good to keep an eye on your fish to see if everything is fine. Monitor the fish and hope that it will get better with the treatments that you’re giving it.

Give the fish the most stable environment possible while treating it. Monitor the water parameters very closely and try to ensure that it eats high-quality foods.

Final Thoughts

You’ve learned that when cory catfish have red bellies it’s an indication that they have contracted red blotch disease. This is a disease characterized by red sores on the skin.

These sores most commonly appear on the belly of the fish. They can also appear elsewhere on the body, but they’ll usually be most concentrated around the belly.

It’s possible that many of the sores will be bloody. Some of them could also be clean, but they will have dangling dead skin.

They often look like blisters, and they’re not going to be fun for the cory catfish to deal with. The sores are caused by a bacterial infection.

Generally, fish that get infected will become infected because of poor water conditions in the fish tank. You might not have been monitoring the water parameters closely enough.

Big fluctuations in the tank can shock the fish and make them prone to infection as well. Even using the wrong substrate material can play a role.

Treat the fish by solving problems in the tank and giving it antibiotics. If you catch the issue quickly, then the fish will be more likely to recover fully.

Red blotch disease can and will kill fish. If you don’t treat the fish fast, then it can kill a fish over the course of weeks or months depending on how fast the infection spreads.