What are the bubbles at the top of my betta fish tank?
Have you ever seen clusters of bubbles on the water’s surface in your betta fish tank?
These are called bubble nests and they are a completely natural behavior of a betta fish – in fact bubble nests are a good sign that your fish is both healthy and happy.
Why do betta fish build bubble nests?
It is all to do with the breeding process. In the wild, male bettas cluster small bubbles on the water surface, or underneath floating debris and leaves to build their nests.
The male betta will guard its nest and will wait for (or find) a female to spawn with. Soon after spawning the female betta fish releases eggs. It is the male betta fish’s job to swiftly capture the eggs in its mouth and place the eggs securely into the bubble nest.
Why are the eggs kept in a bubble nest?
In the wild betta fish habitats are often quite dirty, shallow, puddles without much oxygen. Securing eggs inside bubbles means that they are kept moist and are surrounded by oxygen-rich air – and this is why betta fish build bubble nests.
Aside from releasing the eggs, the female betta fish do not play any role in raising or protecting the young. It is the male’s job to fight off any potential threats and to guard the nest (and especially the eggs). If any eggs fall from the nest they pick them up and secure them back into place. The eggs will hatch after a few days, but the fry continue to stay under the bubble nest’s protection until they can survive on their own.
How often do betta fish build nests?
Well, you have learned the reason betta fish build bubble nest is because it forms part of the breeding process. However, bubble nest building comes instinctively to the male betta fish even without the presence of a female.
Almost all males will a blow bubble nest from time to time, with no other reason than it having a natural urge to do so. If you do see a nest in the tank it is a very good sign that your betta fish is happy and healthy. However there isn’t a ‘normal’ time frame or a ‘normal’ size for a betta bubble nest. Each individual betta fish has a different pattern.
Sometimes a betta fish will build bubble nests weekly or monthly (or daily) and sometimes these nests will be nothing but a few bubbles whereas other times they may be up to an inch thick and span a full corner. Don’t worry too much if your fish doesn’t build bubble nests, it doesn’t have to mean your betta fish is lonely or unhealthy. There are many factors at hand, health, water parameters, age and the individual fish at hand.
Betta Tip: A reason your betta fish may not blow a bubble nest is that the filter of your tank is causing too strong a current at the top of the tank
How to encourage bubble nest building
A few factors that will create the best environment to promote your betta fish to build a bubble nest:
- Ensure your filter is set to a gentle flow – especially if it causes a current at the water’s surface
- Floating ‘debris’ – such as Amazon swordplant leaves or even the lids of plastic cups will often end up with a bubble nest underneath
- A very warm temperature – ensure your tank is heated to 78-82 degrees Fahrenheit
- Clean water – betta fish in need of a water change will often lose interest in building bubble nests
- The presence of a female (or a strange male) betta fish will also increase the urge for a betta to build a nest
In the end, betta bubble nests are interesting to observe, a good sign of health and happiness but not necessary unless you are breeding.
All the images on this post were submitted by the followers of our Twitter account!
Thank you to @hprincessw @Ingridvpty @_KaylaJoy_ @KatieBeltrame and sorry if you submitted a pic and it wasn’t used! Maybe next time! 🙂
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Last Updated: October 17, 2021