The requirement of pollution-free fry cultivation is to cultivate the newly hatched larvae to a size of 1.35 to 1 cm, and then transfer them to large-scale fry cultivation. In order to improve the survival rate of fry, fry should be temporarily raised in cement pond or cage before entering the culture pond. The cement pool can be round or square, with an area of 1-2 square meters and a water depth of .7-.8 meters. It can temporarily support 1,-15, tails per square meter, and the water flow rate should be 8-1 liters per minute. Feeding rotifers is the best feed. The net cage has 4 to 5 meshes, and the height is about 5 cm. The stocking density of fry is about 1 thousand per square meter, and the temporary breeding time is 4 to 5 days, and then the fry are transferred to the pond for breeding. 1. Fish fry culture pond: The fish fry culture pond requires convenient water injection and drainage, firm ridges, good bottom material, an area of 1-3 mu and a water depth of .8-1m; 15 to 2 days before the fry go into the pond, the pond should be thoroughly cleaned and disinfected with 75 to 15 kilograms of quicklime per mu.

5 to 7 days before the fry go into the pond, inject 7 to 8 centimeters of water into the culture pond, and after the toxicity of the drug disappears, apply basic fertilizer to cultivate zooplankton, and the amount of fertilizer is 3 to 5 kilograms of fermented organic manure or 3 to 4 kilograms of green manure per mu. ? 2. Stocking of fry: After the toxicity is confirmed by water test, fry can be released, and the stocking amount is 3, to 5, per mu. Before the fry go into the pond, they should be bathed with 8 grams of copper sulfate solution per cubic meter for 1 to 2 minutes to disinfect the fish.

3. Cultivation management: 2 to 3 days after the fry are put into the pond, because there are abundant natural bait organisms in the pond, it is generally unnecessary to add artificial feed, and then artificial compound feed is fed. The main ingredients of artificial compound feed are fish meal, corn meal, soybean meal, vitamins and minerals, etc. The content of protein is required to be 35% to 4%. Throw it three or four times a day. When feeding, first add water to the feed and knead it into a ball, and then feed it. The daily feeding amount depends on the weather, water temperature and fish intake, and the degree is to eat it within 3 minutes after feeding. During the whole fry breeding period, we should patrol the pond every day to observe the fish activities and weather changes; Fill the filtered fresh water once every 7 to 1 days, and the amount of water added each time is about 1 cm, so as to keep the dissolved oxygen in the pool water above 4 mg per liter. After about 2 days of cultivation, the fry can grow into summer flower fish with a body length of about 4 cm, and then they can be transferred to large-scale fish cultivation.