How Do Betta Fish Mate? With Bubbles.

5 min read

Betta fish are among the most beautiful species of fish and they look beautiful in an aquarium.

If you are thinking of keeping betta fish as pets, you might be keeping one of the most wonderful aquarium pets. However, there are certain things you should understand about betta fish. One of them is how they mate which I will explain in detail in this article.


When it is time for betta fish to breed, the male starts the process by building a bubble nest at the water’s surface. Then he will signal to a female to inspect the nest. If the female approves the nest, the two fish will begin courtship which involves chasing each other closely till the female is ready for mating. Then the male will wrap around the female while she lays the egg. Once all eggs have been laid, the male will keep them in the bubble nest and chase the female away.

This may be interesting and strange, but there are reasons for the behavior, and I will explain that now, but let me start with the courtship ritual.

The Courtship Culture

The female betta fish will only mate with a male she considers a match. She uses the bubble nest as the criterion for determining if the male is a match or not. The male knows this and will spend a good amount of time building the nest.

The bubble nest is usually built with air bubbles and saliva from the male. It may take the fish 12 to 24 hours to build it. The size and shape depend on the fish’s choice and preference. Hence the bubble nest varies from one fish to another.

bubble nests are how betta fish mate

After building the nest, the male will signal to the female to inspect the nest. If she approves she will start the courtship. Otherwise, she will swim away or destroy the nest.

Should she stay, the male will move close to her and swim around her. The pair will swim closely together. The male may start chasing the female and may flare his fins at her.

This act may last for a few minutes or may take up to three hours. When the female is ready, she will let the male know, then he will move close to her, turn her, and wrap his body around her.

How Do You Know if the Fish Are Ready?

The male betta fish is territorial; hence he will chase away any other fish around him. Because male betta fish are territorial they should live alone in an aquarium or with a female introduced only for mating.

For effective breeding, it is better to have a separate tank that is used just for breeding. When the fish are ready for breeding, you put them in the tank, and after the process, you return them to their initial home. But this must be done only when both fish are ready for mating. So, how do you know when they are ready?

There are clear physical signs that will let you know when your fish are ready for mating. The color of the male betta will deepen if he sees a female and is ready to mate with her.

He will also begin dancing and flaring his fins. If the female is also ready, her color will equally deepen. Also, her egg tube will be clearly seen close to her ventral fin, and she will develop dark vertical stripes on her body.

betta fish mating

What If They Are Not Ready?

If you are keeping your fish only for breeding then you will be disappointed if they won’t breed.

You can avoid this by choosing the right pair for breeding. When buying betta fish for breeding, you must consider the following factors:

  • Age
  • Health Condition
  • Fin Shape
  • Color

While the color and fin shape will only determine the kind of offspring your fish will produce, the age and the health condition are crucial for the success of the breeding process.

Betta fish are best if they are less than one year old. Also, make sure the fish you are buying are at least four months old. You must check for deformity before buying and properly examine the fish to ensure they are in perfect health condition.

After you are certain that your betta is at least one year old and healthy you can condition them and make them ready for mating.

How to Condition Betta Fish for Mating

Conditioning prepares the body of the fish for mating. It will give them perfect health and put them in the right mood for mating. Betta fish can be conditioned for mating by giving them nutritious food for about two weeks before putting them into the breeding tank.

The conditioning food should consist mostly of live foods and meaty foods, but other nutritious foods will be fine.

What Happens After Mating?

Suppose everything goes right and your fish is successfully mated. In that case, you no longer need the female fish to continue the breeding process.

Naturally, the male will chase it away after he has collected all the eggs. That seems terrible, right? But it is necessary as the female fish will start eating the eggs if she is allowed to stay with them.

However, to prevent the male from hurting her, it would be best if you remove the female yourself.

Once the female leaves the tank, the male will return to its territorial nature. But this time, he will be busy protecting the eggs. If any egg falls to the bottom of the tank, he will pick it up and bring it back to the bubble nest.

The fish may remove the unfertilized eggs from the nest and eat them. The male should be allowed to stay with the eggs till they are hatched. This normally takes two or three days.

After hatching, the male betta may still spend some days with the young fish as they will be unable to swim immediately after hatching. But once they start swimming, you can remove him from the breeding tank.

Now you have your fry(baby fish) to concentrate on.


Let’s summarize the entire process of how betta fish mate.

Betta fish are territorial; hence they are best kept separately but only introduced to a breeding tank for mating and breeding.

Before bringing a male and a female together for mating, it is ideal to condition them for two weeks by feeding them nutritious meaty foods.

While in the breeding tank, the male will make a bubble nest and invite a female to inspect it. If the female likes the nest, she will stay close to it, and the two fish will start swimming close to each other. Then they will embrace with the male turning the female and wrapping himself around her.

They can embrace several times while the female lays eggs. Once the egg-laying is complete, the male will collect the eggs and put them in the bubble nest. The female should now be removed from the tank. Otherwise, the male will try to chase her away and he might injure her. The male will stay with the eggs till they are hatched.

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Pet Aquariums

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