Domestic goldfish reproduce, so long as goldfish can mature, they can reproduce. If the number of males and females in the fish tank is equal, they can reproduce by themselves. Generally speaking, it takes 1-2 years for goldfish to reach adulthood, and adult goldfish begin to breed every spring. However, the time of spring warming varies from region to region, and the specific time of goldfish breeding is also different.

1. Choose parent fish: If goldfish are raised at home, if they want to reproduce, they must select mature parent fish for mating. When choosing parent fish, it is best to choose those with strong body shape, bright colors and no defects in appearance. This can not only improve the success rate of reproduction, but also improve the quality of offspring.

2. Prepare the breeding environment: The breeder should first prepare a separate breeding container for them, and put some aquatic plants in the container, so that the fish eggs can be better attached to it. Secondly, it is necessary to ensure the stable water temperature of their reproduction. Finally, an oxygen pump can be installed to ensure sufficient dissolved oxygen in the water.

3. Reproduction: When goldfish reproduce, the female fish first produces eggs, and then the male fish excretes sperm. After successful insemination, the eggs of male fish will become fertilized eggs.

4. Hatching: After the fish eggs become fertilized eggs, the breeder can keep the water temperature at about 25 ℃, so that the fish eggs can hatch small fish after 2-3 days.