Betta fish are amazing and popular animals to care for. Their fascinating anatomy makes them an interesting topic for many studies, including the way they breathe. If you have been looking around at some bettas or have one yourself, you might wonder how betta fish actually breathe and how they are actually similar to humans.

How to betta fish breathe?

Betta fish breathe using both their gills and by gasping air at the water-surface. In the wild, bettas live in often oxygen-poor habitats which caused bettas finding a way to get their oxygen directly out of the air, using their labyrinth organ.

What is a labyrinth organ?

The labyrinth organ is a lung-like organ situated right behind the gills of fish in the suborder of Anabantoidei. It consists of multiple different folded membranes and compartments. These membranes are surrounded with many blood vessels that extract the oxygen parts from the air.

As you might know, in the wild habitat of betta fish there can be a lack of oxygen. It is not true however that wild betta fish live in nasty and polluted mud puddles or pools. In fact, it is actually the opposite. In the wild habitat of betta fish there are often tons of plants and healthy ecosystem where many species thrive.

By using the labyrinth organ, betta fish are able to survive in oxygen poor water without dying. They do this by gasping for air every few minutes and sucking in the air to their labyrinth organ. After they derived the oxygen they burp it out, our they will build a bubble nest.

Did you know? Because they have the ability to breathe air betta fish can stay alive on the land for way longer than the average fish. They can even live up to a couple of hours out of the water, when their skin and gills stay wet. With no hydration they can stay alive for up to 15 minutes. So if your fish has jumped out of the tank and if you’re fast enough there is a chance it’s still alive.

Other fish with a labyrinth organ

Not only betta fish have a labyrinth organ, all fish in the suborder Anabantoidei have it. The whole suborder is called labyrinth fish, which includes three families of gouramis: gouramis (which includes Betta sp.), climbing gouramis and kissing gouramis

In total there are over 130 species that all have the ability to breathe air, with most of them in the family Osphronemidae being bettas and gourami species. Some common fish that also have a labyrinth organ:

While some labyrinth fish can rely fully on their gills for getting oxygen, bettas and gouramis only get a part of their oxygen out of their gills, and are forced to gasp for air every couple of minutes, using their labyrinth organ otherwise they will choke and die.

Using the labyrinth organ to reproduce

Apart from using the organ to breath, many species also use their labyrinth organ to reproduce. The male builds a so-called bubble-nest where he cares for the fry the first days.

If you have a betta yourself, you are probably familiar with your betta fish blowing bubbles or even making a whole bubble nest which can get up to 10 inches in width. They do this using their labyrinth organ, blowing bubbles out of inhaled air, where they derived all the oxygen from.

If your betta male is doing this, he isn’t sick, he actually feels safe and comfortable. Betta males will only build a nest in a place they feel safe and mark as their own territory. 

Males are the ones who build nests for breeding and will care for the fry, but females can also create small bubble nests. This is usually a sign of your betta female having a lot of hormones in her and is ready for spawning. 

When a male wants to reproduce, he will try to tempt the female to mate and will flair. If it comes to mating, the male picks up the eggs and places them carefully in the nest. If a male breeds for the first time, he might have a hard time caring for the eggs and fry and might eat all of them. The nest provides a place where the eggs can sit and fry can hang on, until they’re ready to swim freely.

Betta fish in the wild will carefully choose the place where they build their nest. They will usually choose a place shielded from the big pools and open waters, in a separate pod which they can easily defend and that’s safe from predators. Bubble-nesting fish only appear in stagnant and shallow water, because in faster flowing waters their bubble nests won’t hold. In faster-flowing water the labyrinth fish will switch over to other ways of reproduction

After the female laid her eggs, the male scares her away and will care for the nest. He will guard the nest and pick up fallen eggs or fry. Until the fry swims, this nest plays a crucial role in development of the eggs and fry.

Although most people know only the bubble nesting species such as Betta splendens and Betta imbellis, there are also a lot of mouthbrooding betta species such as Betta macrostoma.

These species do not use their labyrinth organ to make bubble nests and males carry the eggs and fry in their mouth.

Although most people know only the bubble nesting species such as Betta splendens and Betta imbellis, there are also a lot of mouthbrooding betta species.

These species do not use their labyrinth organ to make bubble nests and males carry the eggs and fry in their mouth.

Do I need extra oxygen in my tank?

Betta fish can perfectly live in tanks without an addition of oxygen provided by a filter or air pump. However, betta fish need a minimum of oxygen in the water to feel good and a filter can be a good addition to improve the water quality.

A common misconception is that bettas can live in small jars or bowls, with hardly any water and very little air. Yes, it’s true that your betta can survive in this, much longer than most other fish, but this doesn’t mean it’s right for them. There’s a difference between being able to survive and being able to thrive.

Betta fish can live in low-oxygen environments, which does not mean they can live in nasty small jars or tubs without any attention. These environments make them weak and they can easily get diseases, or die of unhappiness. Betta fish need oxygen in the water, and will feel much better in environments where there is enough of it.

In fact, in the wild most habitats have oxygen created by plants and algae, so it’s a misconception that there is no oxygen in the water at all. Some habitats are even very rich in oxygen created by small streams coming out in the pools.

In order to thrive they need a big place to feel good with a minimum of oxygen and at least 4 gallons of water, with some plants (the more the better) and hiding places.

Adding air by an air pump or something similar is not recommended because it will be a source of stress, and is not really necessary. A filter is optional, and will probably be only beneficial in bigger tanks (8 gallons+). If your filter creates a lot of current, this can also be a cause of stress since bettas aren’t made for fast-flowing water.

The best way to create a good environment for your betta, with enough oxygen is to add live plants. These will be the best way to add oxygen, and they add natural cover too. By adding plants you create an environment similar to their natural habitat.

Final thoughts

Bettas are very unique fish and can derive their oxygen, if nescessary for 100% out of the air. They do this using their labyrinth organ. Males also use it to reproduce and afterwards, the fry will develop their own labyrinth organ gradually. It is a myth that wild betta fish live in nasty or polluted water. To make your betta happy choose a tank at least 4 gallons with some plants and possibly a filter, but most importantly clean water.