Gill Hyperplasia Betta – Causes And Treatment

Gill Hyperplasia Betta is a typical phenomenon that causes the gills to become swollen and red. What causes this disease? Which treatment can be applied to heal it? Let’s follow us to find the answer.

What Is Gill Hyperplasia In Bettas?

First, what are gills and how do they work? It is an organ on the side of the fish’s head and helps them breathe by taking in oxygen.

Gill Hyperplasia is an increase or accumulation of cells in fish’s gills, forming tumors. In other words, the gills and seminal vesicles are red and swollen. It hinders the fish’s respiration, causing them to breathe harder and faster than usual.

This phenomenon is commonly seen in bettas because their gill tissues are extremely sensitive and vulnerable to external factors. Poisons in low concentrations are enough to cause gills to swell.

When preventing the bettas from absorbing oxygen from the water, gill hyperplasia can cause them to die. Common symptoms of this case include swollen or enlarged gills on one or both sides.

In addition, the eyes of the common bettas are black, and they may have gill hyperplasia if you see them turn white, red, or even lose color.

Gill Hyperplasia In Betta

What Causes Gill Hyperplasia In Bettas?

The culprits behind gill hyperplasia in betta fish might be as simple as injuries and more serious like toxins, bacterial gill disease, and especially gill flukes.

Gill Flukes

Gill flukes betta, or Dactylogyrus parasite, is a parasitic fluke in the gills of bettas. They are like small worms that multiply and develop in the gills of fish, secreting mucus that clogs the gills.

They are produced from polluted water tanks that have not been cleaned for a long time. Despite being harmless in an aquarium, they can cause inflammation and other gill-related problems.


Toxins from high levels of nitrite, nitrate, and chlorine make the habitat of bettas a breeding ground for disease.

These toxins are derived from fish waste and their leftovers. Decomposing these organic substances takes a long time, so they will turn into toxins once they accumulate.

If you do not regularly change the water in the aquarium, these toxins will enter the gills and cause the betta to get Gill Hyperplasia.

Bacterial Gill Disease

In addition to toxins, bacterial gill disease that results from the production of myxobacteria also causes the gills of bettas to swell. It is often seen in aquariums with a high density of fish.

It fosters many other diseases to appear and spread, affecting the health of bettas. The higher the number of infected fish, the more pathogens will accumulate in the water, causing Gill Hyperplasia.


Besides the chemical effects, the physical effects are also linked to inflammation in the gills. Collisions with larger fish in the aquarium also cause betta eye injuries.

The gill tissue breaks down, forcing the gills to become inflamed and take a while to heal. These collisions occur when too many fish are in the tank and the space is not large enough for them to move.

Moreover, decorating the tank with rocks or sharp objects also causes bettas to be injured while moving. Some cannot see the obstacles around them and crash into them.

Injured betta

Gill Hyperplasia Betta Treatment

Change Water & Keep It Clean

Regular water changes are one of the most helpful ways to protect your betta from harmful toxins and bacteria in the water. To begin with, you should replace 50% of the water in the tank with conditioned fresh water so that the fish can gradually get used to it.

You can also add detoxifiers but in moderation. Moreover, the regular cleaning of the tank helps the fish to have a healthy living environment. Leftover food and fish waste will be removed, preventing the growth of bacteria and diseases.

Add Salt

One way to help heal gill hyperplasia in bettas is to use salt. This ingredient is the most effective disinfectant to kill parasites and microorganisms on fish gills and fins.

It would be best to put bettas with inflamed gills in a 3% salt solution to eradicate the harmful bacteria in the gills. Keep them in this solution for about 30 seconds to 1 minute.

Another benefit of salt is that it helps to increase the production of the mucous membrane that protects the gills and eyes of the fish.

Lower The pH Level Of The Tank

pH imbalance is one of the causes of toxicity in gills. So you should lower the pH level in the aquarium.

It will make the bettas recover faster and reduce pain and swelling in the gills. Besides, lowering the pH level must be accompanied by keeping the aquarium clean. You can stop feeding fish for 1 to 2 days to limit their waste.

Eliminate Surrounding Hazards

You should not let bettas live with larger and more aggressive fish. They will injure bettas from bumps, especially in tight aquarium spaces.

Besides, it is not recommended to use rough and sharp aquarium decorations. Collisions with these ornaments can damage its gills. It is best to use decorative plants or flowers and refresh them regularly.


How To Prevent Gill Hyperplasia?

To prevent Gill Hyperplasia in betta, it’s always best to keep your aquarium clean by regularly changing the water and cleaning the tank. Take care to avoid injuring the fish during tank cleaning.

You should not let too many fish species live in a narrow aquarium. Increasing the tank size, if possible, or separating the fish habitat is a good choice.

Finally, changing aquarium decorations that pose a danger to bettas will help them have a safe living environment.

How Long Does It Take For Gills To Heal?

Gill Hyperplasia in betta can take several weeks to heal completely, provided that you ensure a clean and safe environment for the bettas. By keeping the fish in a 3% salt solution for about 1 minute every day, you will see a clear improvement after a few weeks.

Why Are My Betta Fish’s Gills Sticking Out?

Extending the gills is the betta’s way of repelling predators when other fish enter their territory. When the gills are enlarged, they will look bigger, making the enemies afraid.

However, if this happens with constant frequency and the gills show no signs of closing, they may have Gill Hyperplasia.

Betta Fish's Gills Sticking Out


Overall, toxins, bacteria, and physical contacts cause Gill Hyperplasia Betta. It would be best to keep the fish’s habitat clean and safe to avoid this disease in your fish. We hope this article will help you with your betta caring journey.