The water temperature is 5 ~ 26 degrees, and the water quality pH is 5.6 ~ 6.5. The adjustment period should be carried out slowly to allow the parent fish to have an adaptation process (or choose double distilled water with extremely soft water quality, adjust pH and aerate for standby). Put a pair of parent fish at night. Generally, the female fish will hatch their larvae at dawn the next day, and the larvae will swim to feed after 4-5 days. Female fish hatch 200 ~ 300 eggs at a time. It is difficult to breed at traffic lights, mainly because the breeding requires high water quality and special care for larvae. Soft distilled water should be used for cultivation, then the pH value of water should be adjusted to 5.6 ~ 6.5 with sodium dihydrogen phosphate, then it should be inflated with a larger air pump for 2 ~ 3 days, and then it should be poured into a big glass envy bottle for later use. Spread a layer of nylon net on the bottom of a large glass bottle (diameter 90mm, height 180mm, depth 130mm), spread a little grass on the net, and put a pair of parent fish in each bottle. In order to increase the yield, the incubator usually needs 50 ~ 100 glass bottles. At night, pairs of parent fish are put into glass bottles and covered with paper to create a dark environment. Generally, spawning begins the next day, and it is observed once in the morning around 10. Any parent fish that lays eggs should be fished out immediately, and the parent fish that does not lay eggs can be left in the bottle, such as the bottle that does not lay eggs on the third or fourth day. Parent fish should stop eating during spawning to avoid water quality deterioration. For bottles that have laid eggs, focus on one corner. At 9 ~ 10 in the evening, there will be an artificial egg picking job, and all unfertilized white eggs in the bottle will be sucked out with a straw. The fertilized egg will hatch in a fish tank with a size of 30cm× 25cm, and the water used in the incubator will be poured on the upper layer of the spawning bottle. Because the aquaculture water at the traffic lights is slightly acidic and highly soft, it must be used. 400 ~ 500 eggs are concentrated in each tank, and larvae hatch after 48 hours. The water temperature is always kept at 25 degrees, and it is best to paste paper around the tank to prevent the larvae from being deformed due to excessive light.