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Spawning and Raising Betta Splendens

© Ursula Bosnjak for Betta United

Betta splendens are loners in their natural habitat. Both sexes get temporarily together for spawning purposes only. The spawning process and raising of the youngsters takes place at waters densely planted with minimal water flow in regions like Thailand, Cambodia, Vietnam or Indonesia. Betta splendens build bubble nests. The tasks of raising the youngsters and building the nest are usually taken over by the male – while the female is responsible for the defence of the outer areas around the nest. When planning to spawn bettas in a breeding tank, those conditions should be taken into consideration and provided in a similar way.

Some aspects however have to be considered before the spawning of betta splendens. As generally known, raising fry takes a lot of space and time. Therefore this should be taken well into consideration beforehand. For the following minimum necessities adequate space has to be provided: Besides the tanks where the bettas live permanently, there has to be space for the breeding tank. A 25L tank is usually the best choice – additionally you will need a grow out tank for the youngsters, where they will be transferred to after about 8 weeks (depending how fast they grow). Depending on the size of the spawn you have to choose the size of the tank. For about 50-80 youngsters a 60-80L tank will be fine – about 200L for 200+ youngsters. Also there should be a possibility to have 2-3 bookshelves or similar, where the separation boxes à 3,5L for the young males are put in (about 100 of those boxes should fit in there). Wherever you put those shelves, the room temperature there should be about 26-30°C in order to provide a minimum of 25°C water temperature. Of course there are different possibilities to heat the separation boxes, e.g. heating mats or drip systems. Also you have to keep in mind that the youngsters have to be fed with freshly hatched artemia, which you also have to breed – additionally also micro worms and/or vinegar eels are very useful. In the separation boxes every 2-3 days you should do a good water change – this may take some time if you have about 100 boxes (every week or so you should thoroughly clean all the boxes too).

Of course you should also have a good plan where to give the young fish to – no doubt the youngsters cannot stay forever in those boxes. When they reach about 4cm body length they are ready for their new owners and their own tank. It is wise therefore to contact local pet stores and/or interested people before breeding, to avoid to keep the young males for too long in their boxes. From 4cm body length on those boxes simply become too small for the young fish and even with a lot of regular water changes it is barely possible to keep them there well.

Whenever those preconditions are created, you can start with the preparations to spawn your bettas.

The chosen fish should of course be healthy, vital and well fed – the pair now has to be conditioned for spawning with a lot of high quality food for about 2 weeks (best is good live or frozen food, e.g. artemia, white and black mosquito larvae). Ideally both tanks are now next to each other, in order to have them see each other for about 10-15mins per day (not permanently!!!). This will enhance the building up of a lot of eggs in the female and motivates the male to build a nest.

Regarding breeding tanks, a few concepts exist, how they can look like. Ideally there is a well cycled filter - although not exactly necessary – but it can keep the water parameters more stable then in tanks without a filter. If you decide to use a filter, it is best to choose a sponge filter, as it is not dangerous for small fry. It can be used at all times during the spawning process. If you however chose a regular internal filter, the water flow has to be turned down to almost zero. The filter has to be wrapped well in filter tissue so the fry are not in danger to be sucked in. The whole filter then can be wrapped with e.g. a sock. The filter now is placed horizontally, the filter flow directed towards a close corner in order to have only a minimal water movement inside the tank.

Essential however is to use a small heater that provides about 27°C in the tank. It is wise to place the heater close to the filter (if any), because the male will not build a nest there for sure.

To help the male building a nice nest, it is recommendable to use floating materials in the breeding tank, like almond leaves (that additionally are a bit antibacterial and antifungal), banana leaves, styro pieces, floating plants, etc. It is necessary to also cover the breeding tank of course. Ideally the tank is filled with a maximum of 15cm water.

During the night a little lamp should be left switched on somewhere around the breeding tank – the male is always busy to pick up eggs that are about to fall down from the nest, also during the night. The light can help him to find them easier.

Before the spawning process and until the female is removed from the tank again it is better however to shut the lights off completely. If necessary it is easier for the female to hide from the male.

As you should not touch the breeding tank during the spawning and not disturb the pair in any way, it is a good idea to release a portion of live daphnia beforehand. This way high quality light food is always available that also does not hurt eggs or small fry later on.

Regarding the rest of the interior of a breeding tank there are several possibilities, that all have their pros and cons.

bare tanks: In the tank there is only a heater (optionally also a filter maybe), plus swimming nest building enhancers and hiding possibilities for the female e.g. java moss, delicate dense plants, caves etc. The bottom remains free of sand or gravel. The advantage is mainly the hygienic situation is such tanks, because you can clean the bottom better, as well as see and avoid the youngsters easier while doing that. Also for the male it is easier to pick up all the eggs from the bottom

tank with complete interior: In those kind of tanks you will find the same interior as in the sterile ones, but it includes sand or gravel on the bottom and plants growing in there. The tanks are fully cycled. Here you have all the advantages of a cycled tank with the associated stable water parameters. However you cannot keep it as clean as a sterile one as the exact cleaning of the bottom is not possible. Also you are at higher risk to suck fry in with the dirt too and it takes a lot of effort to pick them all out again of the waste water.

“dark” tanks: Over a sterile tank a dark towel or cloth is put. An about 3cm hole is being cut in there, above a little light is placed. The best place for this hole is right above the area where the least water flow in the tank happens. The advantage of this setting is mainly to be able to spawn rather aggressive fish, because it provides more safety for those. Chasing simply stops when they cannot see each other in some areas of the tank. The important area by the nest however is light enough. Additionally you can also darken the water a bit e.g. with 1-2 almond leaves or with a few dry cones of an alder tree. After the successful spawn when the female is being removed also the dark cloth is taken off from the tank again.

Most of the times it is wiser to first put the female into a breeding tank and let her check out the tank for a few hours calmly. Then she is being put in a see through plastic cup/bottle or behind a see through divider. Especially the area close to the filter is suitable for that because the male would not build his nest there anyways. Whatever device you choose to keep the female separated in, it should be easy to be removed later on – without moving the water too much to not damage the nest.

Now the male - separated from the female - will be put into the breeding tank. Usually whenever he sees the female he will soon start to build the nest. As soon as the nest seems ready and the female shows vertical light stripes on her body (signalling she is ready for spawning) you can release the female. In this phase you should watch the pair very closely (except of course in dark tanks where this is not possible but anyways a lot safer for the fish). Ideally after a bit chasing and fin nipping the pair is ready to spawn. The male now tries to lead the female under the nest. However if the chasing becomes endless and lasts for days or if the nipping becomes brutal biting endangering the health significantly you should decide to put the female back in the dividing device and try again some time later.

As soon as the pair is under the nest, the first spawning attempts will happen soon, after those the real spawning happens. The male will try to wind around the female and squeeze eggs out of her. The eggs are fertilized then and put into the nest.

Now you should turn off any interior filter – after the youngsters can swim freely plus 2 or 3 days you can turn it on again – however watch carefully if the flow is really low enough to not make the fry stick to it.

After the spawning the male will now start to ruthlessly chase the female away from the nest. Now is the time to take the female out of the breeding tank. During the next days she should be fed well and if necessary you can add a bit of salt to her water so that her wounds can heal better (1 flat teaspoon per 10L of water).

Now the most effort taking phase starts for the male. Taking care of the nest and the very young fry is a time he will neither sleep nor eat (however some males do eat a bit). Until the young fry can swim on their own he is at all times under the nest and checking for falling down eggs (or fry later) to put them back up into the nest. After about 36-48 hours the eggs hatch. At the beginning it is quite tricky to see the tiny fry; they look like little commas hanging down from the nest. The male continues to watch the nest and will put escaping fry always back in it.

During the first 2-3 days the fry will have food through their yolk sack and from infusoria (if there are plants in the tank). From about day 3-4 on however fry have to be fed with e.g. microworms or vinegar eels. Also fluid nutrition is fine in the very beginning. Whenever they swim on their own though (now the male gets removed usually and should get good food and rest) freshly hatched artemia should be offered. A little bit of well aged water can be filled into the tank now also – slowly and carefully (with an air tube this works well usually). A few days after the fry can swim on their own also the filter can be turned on again – please watch it well though in the beginning and check that the fry wont get stuck on it. As soon as the tank is filled up (which will happen with a little bit of water daily added), the filter can be turned vertically again.

After 1 ½ -2 weeks the ground should be cleaned for the first time (careful to not or barely suck fry in too – check the wastewater under a very bright light before it is thrown out). 2 weeks after hatching water changes can begin too, in slightly larger amounts then before because the fry are not so extremely sensitive anymore to changes in water parameters – about 20-30% every 3-4 days is fine now. A few snails can also be put into the tanks whenever the fry can swim on their own – they can help to keep the tank clean.

For the next 6 weeks artemia nauplia are the main food for the fry. They are high in proteins and help them grow better then many other kinds of food. Feed 2-3x a day. Only feeding with micro worms or vinegar eels should be avoided, as they cannot offer enough nutrition for a fast and healthy growth.

In week 4-5 you can try to eventually feed the youngsters also with dry food – especially decapsulated artemia eggs, cyclop-eeze and the like is regarded as good food now. Later on, in week 6 you can also start to feed defrosted Cyclops as well as red plankton. Every new food will at first be refused or at least be regarded quite sceptically. However eventually they get to really like it.

Starting with week 8-10 the size of the tank should be critically evaluated and maybe the fry should be already moved into the grow out tank. Grow out tanks should be cycled and have a complete inventory. You can also put snails in there and/or even a group of smaller corydoras (if the tank is big enough) – both are not only nice to look at but also a great help in keeping the tank cleaner. Frequent large water changes are still a necessity to enhance the growth of the fry although the tank is larger then the breeding tank (30-40% every 3-5 days minimum). The bigger and closer they get to puberty the often and the more water should be exchanged. Some breeders think that the fry release certain hormones to the water that seems to inhibit the growth of the fry, but however also nitrite and/or the so called “crowding-effect” could be responsible for this.

Starting at about week 10 you will be able to see the first quarrels between the fry in the tank. As soon as this turns into rather biting or even tearing out fin parts it is high time to separate the most aggressive fish into separation boxes. Choose boxes of about 3-3,5L that are also safe for food, completely see through and either plastic or glass and coming with a lid. Per box of course only 1 fish is housed. The water inside should have 25-26°C, every 2-3 days you should do a good water change and also clean the boxes completely. Feeding can be reduced to once a day now. Depending on their size you can also start to feed them with defrosted daphnia, cut white and black mosquito larvae and grown out artemia. Avoid at all times permanent visual contact to the neighbouring boxes. However in order to help the young fish to develop good finnage it is recommended to let them see each other for a few minutes per day. Although the boxes are covered, enough air has to get in (you could make a few little holes in the lids – or leave the lids a little open, but be careful bettas can jump very well).

When the youngsters reach a body size of about 3,5 -4cm they are ready to be given to their new owners. They now need their own regular sized tank. In the grow out tank there will be also fishes left – the females. If they are a peaceful group they can stay together in a tank that is big enough for them. However also in the boxes can be a few females that behaved very aggressively and were therefore separated – those females should remain separated also in the future. Keeping them in a group will not be possible.