how does a betta fish make a bubble nest

what does a betta bubble nest look like

You may notice that from time to time a nest of bubbles appearing on the surface of the water of your aquarium, or underneath any floating debris. The first time you see this it might be worrying but be assured that this is a very good sign that your Betta fish are thriving and very comfortable in their environment. Conversely, you may want to promote nest building and your Betta has not yet built a nest. I will now explain what a bubble nest is and why your Betta builds a nest. By understanding this you may also be able to trigger nest building within your aquarium.

What is a Betta Bubble Nest?

A Betta bubble nest is a mass of bubbles that are produced by your Bettas. This is usually at the surface of the water. Often called foam nests, this behavior is typical to aphrophils. Aphrophils are fish who create bubble nests and guard their offspring who are placed within the nest. Other examples of aphrophils are swamp eels, climbing gourami, Asian leaf fish, African pike, armored catfish, and electric eels. Aphrophils tend to live in shallow muddy environments which is why they create bubble nests. Each bubble will then provide an oxygen-rich environment for their young to grow. A bubble nest is often mistaken for frog spawn as it is quite similar in appearance, especially when it contains eggs.

Why does my Betta build a bubble nest?

The bubble nest will always be produced by a male Betta. This is part of the courting ritual with Bettas. The building of a bubble nest is also a marking of territory. In the wild Bettas will mark their area by building bubble nests. This also is used to attract females so the breeding cycle can be maintained. So where a Betta feels he is the boss and is happy in his environment he is highly likely to build a bubble nest. You will already be aware that it is not advised to keep more than one male Betta in a home aquarium. They will most definitely fight and this can result in the death of one of the fish. Bubble nest sizes can vary depending on the size of the male and how motivated he is. Males will, however, build nests whether a female is present or not. If you introduce a female to your aquarium you may often witness your male Betta frantically building his nest due to the courting ritual being triggered. The purpose of the nest is to house eggs and protect hatched fry. The nest will keep the eggs as safe as possible from predators. The bubbles provide good clean oxygen for the eggs to hatch and the nest also keeps the eggs in one location where the male Betta can keep his attention on his growing family.

Betta males are able to reproduce from 8-12 weeks old and it is from this point that they may build bubble nests. They do this by going to the surface of the water and taking in air. The Bettas will then blow out the air, surrounded by saliva, which produces the bubble. Bettas will do this very quickly and sometimes for hours at a time until they are happy with their nest. Nest sizes to vary so do not worry if the nest is small. The behavior of building a nest, no matter what size, should be viewed as a very positive thing.

If a female is present, the male will then aggressively pursue the female. Males are even known for attacking the female and damaging fins. Some males, if they choose to reject the female can even kill the female. If however, the male accepts the female, they go through a ritual of embracing and during this ritual the female will release her eggs. The male will then release his sperm and spawning occurs. This is the only part the female will play in the breeding process. This would be the time to remove the female as her work is done. The male pretty much does everything else. Firstly, he will meticulously collect the eggs and put each one into the nest. This is where the eggs will stay, carefully guarded by the male until they hatch into fry and able to fend for themselves. Each bubble provides an oxygen-rich environment for each egg to grow. If at any point an egg drops out of the nest the Betta will carefully collect it and put it back in the nest. He guards the eggs very carefully and even if just one egg drops out of the nest he will see it and place it back in the nest.

It is advised that once the fry are visible that you remove the male and allow the fry to grow and fend for themselves. Bettas do not rely on any extended parental care and can thrive on their own after only a few days.

Breeding Bettas is quite difficult and requires careful research and understanding before attempting. I would recommend reading as much as you can to properly understand the risks to allow your self the best chance of success. If you get this wrong you could end up losing fish.

Watch a male Betta building his first bubble nest

How long do Betta bubble nests last?

This is dependant on whether the nest is used to raise fry or not. If the nest contains eggs then they will hatch within 2-3 days of spawning. The fry are able to stay connected to the bubble nest with cells on their bodies. The fry will stay attached until they are ready to feed for themselves at which point the nest will slowly disappear. This will be up to 12 weeks.

If not holding eggs then the nest will last a similar length of time but more likely to disappear sooner than if they are holding eggs. Nest will eventually disappear simply due to the air escaping from the bubbles.

How do you get your Betta to build a bubble nest?

If your Betta has not yet produced a bubble nest there are things you can do to try and encourage bubble nest building. Male Bettas do not always build nests in captivity however as stated above, as a sign of marking territory, the Betta will build if they are comfortable in their surroundings and are generally happy and healthy. Do not worry if your Betta is not building a nest this doesn't mean he is not happy, Bettas are just very fussy creatures. An additional consideration is whether any filtration you are using in your aquarium is causing movement of water. This can also impact whether your Betta will successfully build his nest. Bettas also like to build bubble nests underneath floating debris so this may be another idea for encouraging your Betta to build.

Whilst building a bubble nest is instinct behavior of the male Betta you can almost always guarantee bubble nest building by introducing a female. This will enhance the natural instinct sufficiently for the male to commence a courting ritual. As stated above, males can reject a female so watch the interaction very carefully. If 'embracing' is not taking place then the male could turn and attack the female.

An important consideration is to have the right water temperature and ensuring your water is clean and at the right pH level. Keeping Betta fish does demand quite specific conditions and this becomes even more important when breeding conditions are required. Temperature is key, ensure your water is 78-82 degrees and with an acidic pH which mimics its natural environment. We need the water to be clean however, do remember that, Betta's natural surroundings are usually quite dirty as they prefer stagnant shallow water for breeding. This means that whilst you will need to keep your tank clean, having it too clean can also put your Bettas off nest building for breeding.
Ultimately, if you are able to create the perfect breeding conditions then bubble nests will be highly likely to appear but there is a very fine balance to find and this could take some time.

Is it ok to destroy my Bettas Bubble Nest?

Whilst you want to promote a good environment, and seeing your Betta produce a bubble nest is exciting because this means you have created the perfect environment for him, there are times that you may need to destroy the nest. If there is no female present which will mean there is no risk that the bubble nest contains eggs, then disturbing or destroying the bubble nest is ok. The main reason you may wish to destroy the nest is when you need to do a partial water change. It is very important to continue undertaking your partial water changes because this will maintain the good environment you have created. If your betta has already created a bubble nest, and your aquarium conditions remain ideal, then he is very likely to create more nests.