The Life Cycle of Siamese Fighting Fish

Siamese fighting fish (Betta splendens), also commonly known as betta fish, are familiar sights in the aquarium trade. Despite their flamboyant fins and bright colors giving them the look of a fragile, exotic species, Siamese fighting fish are actually hardy fish that breed readily in captivity.

  1. Courtship and Mating

    • To house the eggs and to attract a female, the male builds a nest of bubbles of air held together with mucus. When the female is ready to spawn, she develops dark bars on her sides. Courtship is often quite lively, and the pair may fight -- although not usually to the death. If you are breeding Siamese fighting fish, include plenty of large growing plants, which provide hiding places. The female in particular needs to be able to escape the male̵7;s attentions.

    Eggs and Fry

    • As well as creating the bubble nest, the male also takes the role of caring for the eggs and the resulting fry ̵1; newly hatched juveniles ̵1; that emerge about a day after the eggs are laid. Although the male cares for his brood, replacing any that fall out of the nest, he may also eat some of them, usually those that are weak. In a cramped tank, the chances of the male eating more fry increase. Hobbyists usually remove the female shortly after the eggs are laid, then remove the male a few days later, once the fry start swimming freely. The fry grow rapidly and will start fighting as they grow. Once you notice this behavior, it is time to transfer them to separate tanks.

    Maturity

    • Siamese fighting fish reach sexual maturity at about two to three months old. If you care for them properly, they should live for two to three years or more. The reputation this species has of dying quickly is due to inappropriate care rather than a particularly short lifespan. At maturity, Siamese fighting fish are highly territorial. Males establish territories and fight hard to keep them. In captivity, you should never keep more than one male in a tank, and always ensure he cannot see another male in a nearby tank. Take care with reflective surfaces, including the tank glass. If a male sees his reflection, he̵7;ll think it̵7;s another male and become stressed. The females are not quite as aggressive but are still territorial. If you have more than one female in a tank, ensure that you also provide plenty of plants, rocks and other hiding places, and be prepared to transfer one if they start fighting.

    In Captivity

    • Although it is fairly straightforward to breed this species even if you are new to aquariums, it is inadvisable to start such a project unless you are certain you have the space or can find homes for all the juvenile fish. Remember that Siamese fighting fish are not social and you cannot keep all the juveniles together once they mature, no matter how large your tank. If you are confident you can care for the young fish, breeding requires at least three tanks -- a breeding/nursery tank and one tank each for the male and female.