When a fish is gasping for air at the water’s surface, it is often a sign of something more sinister. However, with betta fish, this is usually not the case. Having looked into this topic in some detail, I decided to write this post to clarify why it is that bettas gulp air.
So why do betta fish gulp air? Betta fish gulp air at the water’s surface as a supplementary means of absorbing oxygen. Unlike most other fish who can only draw oxygen from the water using their gills, betta fish have an additional labyrinth organ which works very similarly to a set of lungs. This means they are able to breathe both water and air.
Throughout the rest of this article, I will explore how this special adaptation affects bettas behavior and what we need to do as owners to meet their specific care needs.
What Is A Labyrinth Organ And How Does It Work?
The labyrinth is a rather unique organ which is only possessed by a select few species of fish known as labyrinth fish or anabantoids.
Labyrinth fish have evolved with this adaptation to help them survive in stagnant, oxygen-deficient water. Such conditions typically arise in tropical shallow waters, particularly during the dry season when water levels fall.
The organ itself is a specially adapted extension of the gill plates which are the bones that the gills are anchored to.
It is comprised of a network of tiny boney formations known as lamellae. These are tiny membranes, through which oxygen can pass through and be absorbed into the bloodstream.
The name “labyrinth organ” is derived from the organ’s complex, maze-like shape.
When bettas take air into their mouths, it is then pushed into the labyrinth organ so that oxygen may be absorbed.
Characteristics Of Labyrinth Fish
Other than swimming to the surface for air, one characteristic which is fairly specific to labyrinth fish is that they often build bubble nests.
Building a bubble nest is a predominantly male trait and is actually the 1st step in courtship. Funnily enough, though, there does not always have to be a female present for them to do so.
If your betta is making a bubble nest, particularly without the presence of the opposite sex, it usually means that they are healthy, happy and content with their surroundings.
The labyrinth organ also enables some species of betta to be mouth-brooders. This is when the father carries the fertilized eggs around in his mouth until they hatch, as opposed to them guarding a nest.
Do Betta Fish NEED To Surface For Air?
There are 2 main categories of aquatic air-breathers; facultative and obligate.
Facultative air breathers only require air when oxygen levels are running low in the water.
Obligate air breathers, on the other hand, NEED to surface for air regularly. Their gills are poorly developed and are not able to provide enough oxygen for them to survive alone.
Among all of the articles I have read on the subject, the general consensus is that adult betta fish fall into the second category and are obligate air breathers.
Unfortunately, I could not find any definitive studies or concrete evidence on this but it seems to be the typical standpoint among the betta fish community.
This means adult betta fish should have access to the water’s surface at all times so they can attain enough oxygen to survive.
Interestingly enough though, the labyrinth organ is not fully developed or functional when a betta fish is born. Instead, the labyrinth gradually develops as the fish matures, until it is capable of serving its purpose.
When bettas are still young (in their larval state) they do not need to breathe air [source]. Until such time as their labyrinth organ is fully developed, bettas can survive exclusively from oxygen absorbed through their gills.
Do Betta Fish Require Water Aeration?
While aeration is not absolutely necessary for bettas, I would highly recommend putting some in place.
We know that betta fish have evolved in order to survive in oxygen-deficient waters. Nevertheless, surviving and thriving are two different matters.
Come the dry season in their natural habitat, wild bettas often get stranded in small unoxygenated puddles as the water levels drop.
Many bettas will try to jump astonishing distances in order to reach larger bodies of water but only the strong have even a chance of surviving these horrible conditions.
Sadly, many less fortunate bettas die each year during the dry season.
To go to these lengths to escape stagnant waters, it seems fairly clear that bettas do not enjoy these conditions.
Think of spending your entire life breathing stale air in a stuffy room versus a well-ventilated one with plenty of fresh air. Even if you can survive in both, I know which one I would prefer!
An air stone or any filter that gently agitates the surface of the water should suffice. If you do not have a filter I would highly recommend getting one also!
One thing to bear in mind though is that labyrinth fish will not be able to build a bubble nest if the surface current is too strong.
Betta fish particularly do not like a strong current as they have long fins which can make it difficult to swim in such conditions. Therefore a gentle, low current filter is a must.
Labyrinth Fish Care
In general, caring for labyrinth fish is much the same as caring for any other fish. They need good clean water conditions at the correct temperature, some places to hide, a reasonable night/day cycle and of course feeding regularly.
Nevertheless, there are a couple of things we can do as owners of labyrinth fish to help improve their quality of life.
A lot of labyrinth fish appreciate having somewhere to rest near the water’s surface. A few plants can provide this as well as giving your fish somewhere to hide.
You should also be wary of swim bladder disorders in labyrinth fish. As with any other fish, a swim bladder disorder can severely affect their ability to swim properly.
Usually, one of two things will happen. Your fish will either get stuck near the top of the tank or down at the bottom.
For most exclusive water breathers, getting stuck down at the bottom of the tank isn’t a huge issue, however, obligate air-breathing labyrinth fish need access to the water’s surface at all times.
If your labyrinth fish has a swim bladder disorder and is unable to surface easily, it’s important to lower the water level in your tank or temporarily move them into a shallower receptacle of some kind.
This will help to ensure that your fish can get all of the oxygen they need and will prevent them from getting exhausted from trying to make it to the surface for air.
Swim bladder disorder is usually caused by constipation due to poor feeding habits. I recommend reading this article which covers some good feeding practices for betta fish along with how to treat swim bladder disorders resulting from overfeeding.
What fish are labyrinth fish? Some popular examples of labyrinth fish (also known as Anabantoids) which can be found at most fish stores include Siamese fighting fish, gouramis and paradise fish.
Are Corydoras labyrinth fish? Corydoras are not Labyrinth fish as they do not possess a labyrinth organ. However, they do frequently come to the surface to gulp air which is then swallowed. Oxygen is absorbed from the air inside of their gut.