A Detailed Guide to Goldfish Breeding Methods and Key Techniques

There are two goldfish breeding methods: natural breeding and artificial breeding. In practice, however, the main approach is artificial selection of broodstock combined with natural breeding, with artificial breeding used as a supplement. Let's take a look at goldfish breeding methods below!

Natural Breeding of Goldfish

After broodstock are selected from the pond, they are placed into the spawning pond at a ratio of 1:1, 3:2, or 2:1 female to male; generally, too many should not be moved at once. The spawning pond can be a glass tank, a cement pond, and so on. When male fish develop nuptial tubercles, the males and females will chase each other, and this chasing behavior increases from few to many and from short to long in duration. A few days later, the male will press its head tightly against the female's belly and chase her relentlessly, which is a sign that spawning is imminent. During this time, spawning nests should be added to the spawning pond promptly. The materials for spawning nests vary by location; generally, spawning nests are made from hornwort, Myriophyllum, palm fiber rope, plastic flowers, bundles of algae, and so on. After these different materials are cleaned and treated, they are cut into small sections about 30 cm long, tied into bundles of several dozen strands, and suspended in the middle or on both sides of the water layer. Because the water temperature rises, new water is added, and there is stimulation from the opposite sex, the broodstock usually spawn on the second to third day after the spawning nests are placed.

Generally, the peak spawning period for broodstock is from 4 to 10 a.m. At this time, the males and females chase each other in a state of extreme excitement. The female burrows onto the spawning nest, beating the water with her tail fin while releasing eggs, so that the eggs adhere fairly evenly to the spawning nest, and the male then releases white milt, thus completing the fertilization process. Once eggs are generally attached to the surface of the spawning nest, the nest should be removed from the spawning pond promptly and placed into the hatching pond to hatch.

Artificial Breeding of Goldfish

Artificial breeding refers to the artificial insemination of fish species under relatively specific circumstances when interspecific hybridization or natural fertilization has a low success rate. When the selected broodstock already show obvious chasing behavior, first examine the female: use the thumb, index finger, and middle finger of the left hand to hold the female's caudal peduncle so that the broodstock cannot swing left and right and struggle. Then use the thumb and index finger of the right hand, starting from the pectoral fins on both sides of the fish body, to gently press and squeeze toward the anal fin. If there are mature eggs, eggs will be squeezed out; squeeze the eggs into a small enamel basin. Next, gently squeeze out the male's milt in the same way, and use a clean feather to gently mix it so that the milt and eggs make full contact. After a few minutes, the insemination is complete, then thoroughly wash the eggs several times with clean water to remove excess milt. The fertilized eggs can be poured onto the spawning nest to hatch naturally.

Note that throughout the entire process, the water should be clean and the temperature relatively constant, and the broodstock used should also be properly cared for to avoid losses.

Hybrid Breeding of Goldfish

Theoretically speaking, goldfish and crucian carp can be hybridized. The goldfish itself was bred from wild crucian carp, and biologically they are different varieties of the same species. In practice, however, it is very difficult to hybridize goldfish and crucian carp, because the two have undergone great changes in appearance and living habits. When kept together, crucian carp clearly has a physiological advantage, and it is very difficult to get fish with such an obvious disparity in advantages to pair naturally.

Theoretically speaking, artificial insemination of goldfish and crucian carp can achieve successful breeding, but no one would do such a thing, because the offspring of the two would be neither as attractive as the goldfish nor as hardy as the crucian carp; they would excel in neither respect.

Hatching of Fertilized Eggs

Wash the fish pond (tank, basin) clean and fill it with newly aged water, and it can serve as a hatching pond. When the water temperature is the same as the water temperature required by the spawning pond, place the egg-bearing spawning nests into it. Generally, a pond 2 m square can hold about 6 spawning nests with eggs.

The fertilized eggs of goldfish are orange-yellow, semi-transparent, with an egg diameter of 1.0-1.2 mm. Twenty-four hours after fertilization, if the egg turns white, it is an unfertilized egg. The fertilized egg goes through several important stages - cell division, blastula stage, gastrula stage, and larval stage - generally taking 4-7 days, with hatching and membrane rupture depending on water temperature conditions. When the water temperature is above 25 degrees C, the larvae can hatch in 2-3 days.

Goldfish Fry Rearing Techniques

Three to seven days after fertilization, the larvae break out of the egg membrane and enter the rearing stage, at which point the fish body is 1.5-2.0 cm long. Based on whether the body shape is normal and whether the caudal fin is split centrally into a four-lobed tail, and so on, we keep the superior and discard the inferior, placing the selected larvae into rearing ponds to continue rearing. The stocking density is about 50 fish per sq m, and filtered plankton is added to the pond. If the water is relatively poor in nutrients, 0.25 kg of fertilized water can also be added per sq m to promote vigorous reproduction of plankton. After one month of rearing, the fish body can reach 3-4 cm, at which point a second selection can be made and the stocking density adjusted, beginning the juvenile fish rearing stage.