Breeding Livebearers
When fish show signs of being "loaded" with young (a dark area, the gravid spot, in the anal region), they should be separated from the rest of the fish if possible. This separation has a dual purpose.
First, it prevents the mother fish from being molested by the males that are around the tank; and second, it prevents the newborn young from being eaten by the other fish. The delivery tank need not be larger than one gallon, for as soon as the mother fish drops her young, she should be removed—or she will eat her young herself.
The mother fish should be kept well fed while she is waiting to drop. It is a good idea to have the delivery tank heavily planted. Dense Elodea and Vallisneria, with some Cabomba floating around the surface, will greatly aid the young fish in hiding from their parent, if necessary. Remember to take all precautions when shifting the mother fish from one tank to another.
If possible, take the gallon of water from her original tank; if not, make sure that the water in the new tank is not more than 2°F. above or below the temperature of the original tank and that the pH in both is the same. The temperature should be checked with a thermometer, and the pH may be checked with a pH testing kit.
After the baby fish are born, the mother should be removed immediately and placed back either in the original aquarium or in a tank by herself. If she is put in the community tank, it is a good idea to have more than one female in with her, as a female is usually weak after she has given birth and is easily annoyed by male fish chasing her (especially in the case of the guppy).
