Why and How Do Betta Fish Fight?

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Captive bred betta fish, also known as betta splendens, have a notorious reputation for being considered fighting fish. Maybe you have seen them in their solitary bowls at the pet store, or have simply heard from others about their need for their own enclosure.

However, there are numerous reasons why betta fish fight. Like many other animals in the wild, betta fish are considered to be territorial. Which means, it is important for them to have their own area to create a place of their own.

If you plan on bringing one of these fish into your home, or are simply curious as to why betta fish fight, we will talk about some of these reasons below. 

Betta fish are a species native to the Mekong River Basin, covering a significant portion of Southeast Asia, where they can be found in rice paddies, slow moving streams, and ponds. The areas they live in are usually shallow and thick with vegetation.

Known for first being bred in Thailand, they become popularized over 150 years ago due to their aggressive tendencies. They soon began being bred to have more aggression, bright colors and finnage. Captive bred betta fish are the descendants of these original betta fish.

Why Do Male Bettas Fight Each Other?

Male betta fish have one primary instinct and that is for survival. Everything they do, is in order to not only survive, but to ensure the continuance of the species. In the wild they would normally have a wide expanse of habitat to find where they want to set up their home.

If they were to encounter another male betta fish, they would be able to flare their fins and gills to intimidate the other betta fish. If this did descend into fighting, they would start nipping at each other until one of them gave up and swam away.

In captivity, this isn’t so easy. If they are in the same aquarium, there is limited ability to for the less dominant betta fish to escape out of harms way.

You will also see males fighting in order to protect their offspring. Male betta fish are in charge of protecting the nest and eggs, and if threatened fighting will ensue.

Do Female Bettas Fight Each Other?

Although female betta fish can be less aggressive, they can also still be territorial. You can put them in a group of at least 4-5 female betta fish, known as a sorority, where they will establish their own pecking order.

In order for this to be accomplished, it is imperative that there is enough room in the aquarium for less dominant bettas to get away when needed. However, even with this being done, some female betta fish will be too aggressive and territorial.

Why Do Male And Females Fight Each Other?

Female and male betta fish will also fight each other. They should only be housed together during mating season and then separated after. This is due to female betta fish being known to eat their eggs during spawning.

The male betta fish takes on the role of protecting the eggs, and will attack the female better if he feels like the eggs are being threatened. The males protect their offspring until hatching and will do what is necessary to ensure they hatch, this could include killing the female if necessary.

Do Bettas Fight Other Fish

Betta fish will in fact fight other fish. They will do so if the tank they are kept in is too small and either fish is unable to flee to another space when needed. The tank should be at least 10 gallons and full of numerous spaces to hide. If the other fish resembles another betta fish you can also expect that there will be fighting. They should be kept with fish who do not have bright colors and big fins.

You could also find fighting happens if both fish are aggressive. You should place a new fish in a breeding box first to see how they interact with one another. If either one ends up being too aggressive, it is safe to say that they will not do well in an enclosure.

How Long Do Betta Fish Fight?

Betta fish in the wild would normally on get into a fighting match for a limited amount of time. This could mean it ends immediately after they start nipping each other, or a few minutes. They will continue until one gives up and retreats.

However, in captivity this could last until one of the parties is seriously injured, or dies. This is due to being bred specifically to fight since they became popular in Thailand over a hundred years ago. Many bettas could also die due to the injuries resulting in infections.

How To Stop Betta Fish From Fighting

One of the best ways to stop betta fish from fighting is to keep them away from one another. If you are inexperienced with fish, you should look into which fish would be best to be housed in the same tank.

Ensure that you have a big enough tank that will give each fish in the tank plenty of space to have their own specified territory in the aquarium. This gives less dominant fish the ability to not only flee, but hide if needed.

If you plan on specifically keeping only betta fish in the same tank together look into how to keep same-sex and different sex bettas together without conflict.


Betta fish have a long history of being bred specifically to fight one another, descending back over a hundred years when they became popular in Thailand. We can still see this aggression in the captive bettas we see today.

Although there are many reasons why they will fight, there are also ways you can keep them with others bettas, as well as other fish. Each betta has their own personality and aggression level, so with knowledge and paying attention to how they interact with others, you can have successful cohabitation.

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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