Beta fish are popular pet fish these days. They’re colorful creatures with lovely, long, flowing tails. One reason for their popularity is that they are relatively easy to care for. They can be kept in fairly small aquariums and don’t require complicated filters or other accessories, although they should not be kept in small vases or tiny bowls as some people try to do with them.
Beta fish are also fairly easy to mate, although the mating process does require your supervision. Like many other breeds of fish, male and female betas don’t always get along and the male may injure the female if you leave them unsupervised.
Purchase a male beta and a female beta and put them each in their own aquarium. Feed them a high quality commercial fish food designed for betas and supplement their diet with an occasional live tubifex worm (available at many pet stores).
The male will begin building a bubble nest as he nears readiness to breed. If the female is light in color, you’ll begin to see the shapes of dark colored eggs inside her abdomen as she nears readiness to breed. If she’s dark in color, you’ll just have to trust that she’ll be nearing readiness at the same time as the male.
The Breeding Session
Once the bubble nest has reached a good size and you think your beta fish are ready to mate, plan a breeding session. You’ll need about an hour and you’ll need to be available to supervise them the whole time. You can’t leave them alone, not even for a few minutes. If left unsupervised, the male may harm the female or even kill her.
Place the female in the male’s container. Expect him to behave somewhat aggressively but be prepared to remove her right away if she seems disturbed by his behavior or if he seems to be hurting her. If you have to remove her for that reason, wait a few days, then try again.
The male should embrace the female, wrapping his body around hers. He’ll appear to squeeze the eggs from her body. Then he’ll fertilize the eggs.
As soon as the male begins picking up the eggs with his mouth and carrying them to the bubble next, move the female back to her own container. If you leave her in the container with the male, he may injure her.
Caring for the Babies
The male beta cares for the eggs. If any drop out of the bubble nest, he will pick them up and put them back. The eggs hatch in just about two days.
The baby fish will stay in the bubble nest for a day or two after hatching because their gills are still developing. Once their gills have developed, they will begin swimming around the aquarium.
About two days after the babies hatch, when you see them beginning to swim around the aquarium, you need to remove them and put them in their own aquarium. If you leave them in the aquarium with the male, he will likely eat them.
Ask the Vet. http://www.ask-the-vet.com/breeding-betta-fish.htm . Breeding Beta Fish.