Something that I was really confused about when I first started owning fish was exactly how they breathe. So, do betta fish breathe air?
Betta fish do breathe air, just like all other fish do as well. Betta fish take in oxygenated water through their gills, process it, and absorb the oxygen. Betta fish also have a labyrinth organ, which allows them to breathe oxygen from the air, not just from the water.
Keep reading to find out all of the most important facts there is to know about betta fish respiration and that super interesting labyrinth organ.
How Betta Breathe – Two Ways
What is really interesting to note about betta fish is that there are actually two different ways in which they can breathe. This makes them extremely unique when compared to about 95% of other fish out there.
First, betta fish can breathe using their gills. The vast majority of fish in the world all have gills that function in the exact same way. These skills are designed to extract oxygen directly from the water.
However, unlike the vast majority of other fish out there, betta fish also have a very special type of organ known as a labyrinth organ.
The labyrinth organ is a special modified structure located above the gills. This consists of a network of highly vascularized tissue that is rich in blood vessels.
This is essentially like a pair of lungs, just like human beings have, which allows the betta fish to extract directly from the air above the water’s surface.
Why Betta Fish Have a Labyrinth Organ
You might wonder why betta fish have this labyrinth organ, whereas most other fish do not. It appears as though this is nothing more than a result of thousands and thousands of years of evolution. In case you didn’t know, betta fish in the wild live in some pretty poor conditions.
Most betta fish live in rice paddies and muddy puddles, where many times of the year it is almost dry. This means that betta fish must be able to absorb oxygen from sources other than the water.
Oxygen levels in these rice paddies and puddles often become very low, which means that if a betta fish did not have this labyrinth organ, it would effectively not be able to breathe anymore.
The addition of the labyrinth organ allows the betta fish to extract oxygen directly from the air, therefore allowing it to survive some of the harshest conditions that any fish is known to live in.
How Betta Fish Gills Work
Just to provide you with a better idea of how exactly betta fish breathe, let’s first look at how a fish’s gills work.
First, fish use their mouths to draw water in through their oral cavities, with some fish actively swimming with their mouths open to achieve this, whereas others rely on the motion of swimming to force water through the gills.
Inside of the gill chamber of a fish there are pairs of gill arches. These are hard telegenic or bony structures that support the gills.
Each arch of a gil contains a series of honeycomb-like filaments that are called gill filaments. These gill filaments are the primary sites for gas exchange.
They are densely covered in very small structures called lamellae, which have a rich network of blood vessels close to the surface.
As water flows over the gill filaments, dissolved oxygen in the water that fuses through the very thin walls of the filaments and into the bloodstream.
The oxygen then binds to the hemoglobin in the red blood cells, while also allowing carbon dioxide to diffuse from the bloodstream of the fish into the water.
Then, the water that carries the carbon dioxide exits the gill chamber through the opening called the gill slits, which are located on the side of the fish’s body.
Interesting to note is the principle of countercurrent exchange. This is when the blood flow within the gill filaments flows in the opposite direction of the water that flows over the gills.
This creates what is known as a concentration gradient, which allows for extremely efficient oxygen uptake and for carbon dioxide removal.
The Labyrinth Organ of a Betta Fish
As mentioned above, betta fish have a very special organ known as a labyrinth organ, which effectively allows them to intake oxygen directly from the air. Again, this is designed to allow the betta fish to survive in environments where the water otherwise contains very low oxygen levels.
This labyrinth organ is located directly above the gills of a betta fish. This consists of a complex network of highly vascularized tissue, including many tiny blood vessels and folds. The tissues of the labyrinth organ resemble a maze, hence the name, labyrinth organ.
When a betta fish swims to the surface of the water, they can gulp in small pockets of air from above the surface, which contains oxygen.
The inhaled oxygen diffuses across the thin walls of the tissue of the labyrinth organ and directly into the bloodstream. Simultaneously, carbon dioxide, which is a waste product of metabolism, diffuses out of the bloodstream and into the air space within the labyrinth organ.
The oxygen rich blood from the labyrinth organ then circulates throughout the body of the fish to supply all of the organs and other necessary metabolic processes. This therefore allows a betta fish to supplement the oxygen that may not be obtained through the traditional method of respiring with the gills.
Gills or the Labyrinth Organ – Which Comes First?
Remember that the betta fish going to the surface to gasp for air is really only a secondary measure. Although a betta fish does have this labyrinth organ that allows it to absorb oxygen from above the surface of the water, this is not the primary respiration method.
A betta fish would generally always prefer to breathe using their, by absorbing oxygen from the water. However, if absolutely necessary, the labyrinth organ allows the betta fish to breathe when there is not enough dissolved oxygen in the water.
With that being said, it is therefore essential for you to provide your bank with enough oxygenated water.
If you notice that your betta fish is gasping for air at the surface or even jumping out of the water and gasping, then it is likely that the water itself does not contain enough dissolved oxygen.
How to Increase Dissolved Oxygen Levels in Your Betta Fish Tank
If you think that there may not be enough dissolved oxygen in the water, mainly because you know to see your betta fish gasping for air at the surface, there are some solutions to this issue.
Add More Plants
In case you didn’t know, plants also perform respiration, although it is virtually the opposite of what fish and human beings do. Plants take in carbon dioxide and release oxygen when they respirate.
This means that the more plants you have in your aquarium, the more oxygen they will add into the water, therefore benefiting your betta fish. Of course, this means having live plants, not fake plants.
Keep Water on the Cooler End of the Spectrum
For the record, betta fish require their water to be somewhere between 75 degrees and 80 degrees Fahrenheit. What you need to consider here however is that the cooler the water is, the more dissolved oxygen it can hang on to.
Therefore, keeping the water temperature for your betta fish at the cooler end of that spectrum will benefit them in terms of dissolved oxygen levels.
Water that is 75 degrees Fahrenheit can hold significantly more dissolved oxygen in water that is 80 degrees Fahrenheit. That said, you do need to maintain the ideal water temperature range, which means that using an aquarium thermometer is crucial.
Use an Air Stone
If you think that your betta fish is not getting enough oxygen, the simplest solution is to use an air pump and an air stone to provide the water with more dissolved oxygen.
The bottom line here is that betta fish are some of the most unique fish in the world, and this is because they can breathe in two different ways, using both gills and that labyrinth organ! It’s a fish worth keeping at home!