As far as common fish kept by
hobbyists go, bettas are among the most
difficult freshwater fish to breed. There are, of course, harder fish to
spawn but they're mostly of the rare and expensive
variety. However, they have one of the most elaborate
spawning rituals of any species, and are some of the most rewarding fish to breed as well.
Be prepared to invest a good 3 months to complete the project and do not
start it if you need to go on vacation at any point in the first
month. While it's easy for friends to tend your community tank, keeping
betta fry is very difficult for the non-fish-owner.
Supplies you will need before you even start:
A properly matched pair of bettas, in size and color. They should be of equal size, or the female slightly smaller--but at least 2/3 his body size. Never breed a pair with a significantly smaller male, it is impossible. (See Betta genetics)
A clean tank with no gravel, at least 2 gallons and up to 20. (If you use a larger tank you needn't move fry as much as they mature.
Plants, real or fake, anchored in one corner.
Decorations of a 'cave' type grouped with the plants.
Floating plants (java moss and duckweed work well) in the opposite corner. Alternately, cut the very bottom off a Styrofoam cup and float that.
A 2-liter soda bottle, washed clean with hot water and no soap
A small box air pump with tubing and an airstone.
Sea salt or aquarium salt
brine shrimp eggs
Introducing the pair/courtship
There are several ways to do this. If the pair is introduced before either is ready to spawn, the male may injure the female.
- If the male has been courting the female in a community tank, you may just put them both in the new tank. (Don't do your first spawn this way. Be careful to start until you learn betta behavior better.) ((Say that five times fast))
- Put the male in his tank and wait until he builds a bubble nest, then introduce his lady
- If the male will not nest-build on his own, get a tall jar or bowl, set it inside his tank, and put her in it. She may inspire him to get to work.
- When females are truly ready to breed, unless they are light-colored, they will develop vertical white bars along their bodies. It is safest to introduce her directly to him when she's barred, but if she looks large-bellied, put her in anyways, as she may bar rapidly.
He will nest-build and display for her. He'll flare his gill flaps and "shimmy" through the water at her, showing off his fully-flared fins. If she is not ready to breed, he will chase her away if she gets too close to the nest. If she is, the spawning begins.
Spawning
The female, heavy and barred, will hover tail up head down under the male's bubble nest while he snakes about her. Both fish will be in brilliant color.
Now begins the most interesting part of the whole ritual. He will literally wrap around the female's body, lining up their vents, and squeeze. The fish will be mostly obscured by his draping finnage. The embrace is so strong it literally knocks the pair out and they will float, unconscious, to the top of the water. He usually recovers first and will slide off. The female will float on her side, stunned, for a few moments longer. This part often scares first-time breeders when they see their female floating, but do not worry, that's how it's supposed to work.
As the male slides off and the female floats upwards, the pinhead-sized eggs that were literally squeezed out of the female will begin to fall through the water. A diligent male will grab them in his mouth (he is not eating them) and spit them up in his bubble nest. You can see tiny opaque specks in the clear bubbles. There can be anywhere from one or two eggs per embrace, up to two dozen. The beginning and end of the spawn have fewer, and at the peak, there are the most.
Occasionally, one time in 10 or 20, the male will ignore the eggs. If it's his first spawn, give him time, he often will 'get it' later on. If this is habitual, retire him as a breeder. If he proves to be an egg-eater, retire him immediately.
The females will help egg-gather about half the time. Some are good mothers, some ignore the eggs totally. Females are more prone to eat eggs than the males, so he will often chase her away to gather the eggs himself. In rare cases, the female will tend the nest and the male will ignore it.
This process will be repeated anywhere from half an hour to hours on end. (My current pair has been spawning for three hours and is still only in the middle of it.) Once the female has lost her bars and the male attacks her whenever she nears the nest (leaving her to cower in the plants in the other corner), remove her and put her in a recovery tank for a couple days, or your community tank if it's healthy. If you have a "deadbeat dad" who will not tend the nest (very, very rare) remove the male instead and leave the female--IF you've seen her tending and not eating the eggs.
Hatching the spawn
Until the fry are freeswimming, NEVER turn off the tank light.
The eggs will hatch within 24 to 48 hours. The little white dots will be replaced by tiny glass-sliver tails hanging down from the nest.
Start your brine shrimp culture now, as per instructions on the package. Be sure to drop the airstone and piping in and make sure it goes down all the way to the bottom. The shrimp will not hatch unless the water is fully in motion. If you can find a green water culture, start it now too.
The fry should be free-swimming in 2-3 days. (Until then, the male will seriously have his fins full.) When they ALL go from dangling in the nest to hovering horizontal in the water just under the surface, remove the male. His work is done. Yours is just starting.
Raising the spawn
The fry need to be fed twice daily for at least the first couple weeks. Feed them green water if you have any by pouring 1 / 4 the bowl in the tank. Feed brine shrimp regardless.
You harvest these by removing the filter from the bottle and letting it settle for about half an hour. The eggs will float to the top and sink to the bottom. The shrimp will congregate in the middle. Attract them to a single point by shining a small flashlight. They will congregate around the light. Use another set of airline tubing as a miniature siphon. Siphon them through a brine shrimp net and then wash them in fresh water. Feed to the fry, then refill the bottle. When the fry have eaten satisfactorily, you should see orange blobs through their transparent sides. Throw out the culture and start a new one every 5-8 days or it will begin to smell awful.
Once the fry are 2-3 days old, add an airstone or sponge filter to the tank. This prevents the top from skinning up and suffocating the fry. Once the fry are large enough to not be sucked in an intake, you may use a power filter in the tank. To use one earlier, wrap the intake in cheesecloth. Do not add this, however, until the fry can swim well or the water movement will knock them around too much.
Once the fry get a little larger and start looking more like fish than glass shards (usually at about 1 month) you can buy grown adult brine shrimp to feed them. You can also try—slowly—to wean them onto dry food. Feed shrimp 2 days, feed flake or freeze-dried blood worms 1 day. Observe to see if they"ll eat. When they show any interest at all, you can feed them flake more often, but still feed shrimp every few days to make sure everyone"s getting enough food. There will always be a few stragglers who are slow to wean off live food.
As the fry get larger, about 2.5-3 months, they will start to squabble. Usually, only 3-4 males will grow long fins at a time, the dominant males of the moment. They will begin to pick on mostly other males but really anyone that comes in their way. Whenever you see a fish that"s bullying others, or one that has significantly longer fins than the rest, pull him and put him into his individual jar. New males will "bloom" fins in just a few days to replace the now-missing dominants. Continue this until all the males are out of the tank. Females can remain together indefinitely.
If you do not pull known males early on, they may damage each other"s fins and will be harder to sell. Fins usually grow back out happily enough, but sometimes they"ll remain discolored or bent permanently. Tend jarred males like normal bettas, with proper food and water changes.
Unfortunately, my sources are lost to the years. This is what I remember from many books and webpages when I first researched this some six years ago. The data is widely available but this particular node is from memory, working at a fish store, and my own experience.