Why is Betta Fish Flaring its Gills & Fins?

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Are you concerned about your betta fish flaring gills and fins? Then you have come to the right place. Here, we will take a look at why the betta fish is flaring its gills and fins.

Betta fish flaring is a very specific behavior that only occurs with the bettas. Often, this behavior is seen when a betta is either threatened or when it faces another betta male.

But it is not always a bad sign; it doesn’t always indicate that a betta is under threat or is aggressive towards other fish.

In fact, bettas might flare its gills and fins sometimes just to show its vivid colors and the exciting appearance. Sometimes it might not be a sign of aggression, and is just natural behavior. But, if there is another betta male in the tank, then it is most likely a sign of aggression and threat.

Flaring can even be healthy and natural. It happens once or twice a day, and that is when the betta wants to stretch. You can compare it to our behavior when we stretch when we are at work. It is important because it can help the bettas stretch their muscles.

You can even make your betta flare its gills and fins. That can be done if you just place a mirror next to the tank. When the betta sees its reflection in the mirror, it will flare its fins, thinking that it’s another betta that wants to fight.

Is Flaring Good for Betta Fish?

It largely depends on tank conditions. If you have another betta fish in your tank, then it is a bad sign. It means that two betta males are about to fight. When this happens, they will fight for longer periods, and it can even result in death.

It is for a reason why bettas are also named Siamese fighting fish. If flaring occurs when two bettas meet, we can interpret it as drama, and a precursor to a fight.

It is a matter of dominance, and one fish might try to assert dominance over another.

Sometimes we think of it as macho behavior, a psychological trick to try and scare the other fish before the fight happens. In these cases, it is not good that the betta is flaring its fins. You should try to separate two betta males to prevent fighting.

In other cases, it might just be a behavioral thing. It is perfectly normal to see a betta flare its fins once or twice a day. In this case, you should not worry too much about flaring. When it comes to breeding, flaring is also perfectly normal and acceptable behavior.

When it is used for these two cases, flaring might even be beneficial, as it can help them stretch their muscles and fins, and it also gives you an opportunity to inspect their gills if they are healthy.

Do Female Bettas Flare Their Fins and Gills?

The answer is yes, they do, but it is not a big reason for concern. It is more concerning if bettas flare their gills and fins, as it can be a sign of aggression. When females flare their fins, it is done in a semi-aggressive manner.

Also, flaring with female bettas is quite rare. When they see their reflections in the mirror, they may or may not flare. If it is a sign of semi-aggression, then you shouldn’t worry too much, as females usually don’t fight. Still, keep close attention to your females if they flare their fins, and inspect their fins and gills if they do flare.

How Can You Make Betta Fish Flare?

You can do something that makes the bettas flare their fins, and that is placing a mirror next to the tank, so that the betta will be able to see itself. But that doesn’t mean placing a mirror into the tank permanently. That can even harm your fish.

You can make your betta fish flare from time to time to see their fins and to help them stretch their muscles. But this behavior should not be encouraged too often, as it can put too much stress on them. Also, it is fun and beautiful to see the fins and gills in full span, so many owners try to encourage flaring too often.

A small handheld mirror will be just enough to make your betta flare from time to time. Constant flaring, on the other hand, can be bad for your betta’s long-term health.

How to Make Your Betta Fish Flare Less?

If you are concerned that your betta is flaring too often, then there are some things that you can do to reduce this behavior.

Bettas can be flaring at other betta males, which is a usual behavior, but sometimes they can also flare at other tank mates. If this is a recurrent thing, then it might start hurting your betta over time, and it can cause stress and diseases. That is when you might start to think about placing a betta into a separate tank to avoid this stress.

We have already talked about reflections and flare. Sometimes, it can be used to encourage flaring, but it shouldn’t be a constant thing. It might mean that there is a mirror nearby where the betta might see itself. In that case, remove the mirror, or place the tank in another spot.

Another possible reason for flaring is due to light – it might come into the tank in such an angle that the betta is able to see its reflection. That is when placing the tank into another spot can be good.

In the worst-case scenario, you can always cover the sides of the aquarium to stop the light coming in and reflections from happening. Use an old sheet or cloth to stop this from happening.

Do Bettas Flare their Gills When Stressed?

Stress can be one of the factors for flaring, and excessive flaring can be an indication that something needs to change. But flaring itself is stressful, so you want to reduce stress as much as possible to discourage flaring.

Stress can happen because the bettas might feel intimidated, or if they don’t like their tank mates. If they are unable to do anything about it, they can become severely stressed, resulting in a bad appetite and deteriorating health.

It can lead to a weakened immune system, which can, in turn, lead to diseases, which can even be fatal. Even the harmless of the bacteria can attack the betta and harm it when its immune system is compromised due to stress. Avoid poor tank conditions, feed them quality foods, and make sure they feel safe in the tank.

My Betta is Flaring at Me! Does He Hate Me?

It most likely doesn’t mean that the betta hates you, but it is just that it is either being territorial towards you, or they want some peace, especially if you have been interacting and cleaning the tank a lot. In some cases, it might simply be a sign of the fish’s character, and there is probably not a lot you can do about that.

Another reason why it might happen is if they are new to your aquarium, and they are not yet used to you. It might take some time for them to bond with you. You might look threatening to them at the start; after all, you might look like a big predator waiting to pounce on them.

It is also possibly a sign of stress. Too much stress can lead to aggressive behaviors, and you should investigate it. If you notice anything unusual about their behavior and the surroundings, then you should try to address the issue.

Betta Fish Flaring at Snails and Other Fish – Is this Normal?

It can happen, as betta fish are known as territorial fish, and it is a way of showing their dominance towards other fish. While they might not attack them, you might notice this behavior towards other fish and especially snails, sometimes.

It might be a sign that you need to place the betta into a separate tank. Too much flaring and stress due to other fish or overcrowding are not good, and you should avoid it at all costs.

In some cases, they might be just fine with other fish, and flaring can occur sometimes. It might just be in the betta’s character. But consider all the factors, such as stress levels, the space they have, and the general tank conditions.

If you notice any aggressive behaviors towards other fish, or the betta fish starts acting in a different way than usual, you should think about placing the betta into a separate aquarium.


Flaring can be very exciting and beautiful. It allows us to see their exotic colors and beautiful fins. Sometimes, it is a natural occurrence, while in other cases, it is due to aggressiveness or stress.

In any case, excessive flaring should be dealt with. Otherwise, flaring is a natural behavior for bettas.

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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