The choice of broodstock can be made between September and October of the previous year or March-April of the year. Broodstock should choose more than 10 months old, weighing 30 g -50 g, complete appendages, infirmity, disease no injury, the body is smooth, without attachments, strong activity of the individual male and female shrimp ratio of 2 or 1 :1. Shrimp age females was significantly greater than males; shrimp similar length, male chelipeds thick, outer ends chelipeds a bright red molluscum, female chelipeds relatively small, the majority of the females in no soft cheliped warts, even if subdued color; males gonopore pereiopod base opening 5, females in the third opening gonopore pereiopod base; sexually mature females abdominal swelling, abdominal relatively small number of males. Broodstock broodstock rearing tanks generally use earthen ponds, depending on the size of the area may be. The water depth is 0.5 meters to 1 meters, and the pool width is 1.5 meters or more. After the drainage system is built, anti-stopping walls shall be constructed with plastic film or calcium plastic panels around the pool. The broodstock cultivation pond must be provided with sufficient water, fresh water without pollution, and high dissolved oxygen. In particular, the amount of oxygen dissolved in water during intensive cultivation is required to be above 4 mg/l. Several small ditches were excavated in the pool to facilitate the collection of shrimps. Fifteen days before the broodstock is stocked, the whole pool is disinfected with 150kg of quicklime per acre, and 500kg-800kg of decomposed livestock manure is applied to the water. Then, after filtering (to prevent wild fish from entering the pond), new water is injected, and concealed objects such as branches, tree roots, bamboo tubes, etc. are placed in the pool for the shrimp to inhabit, and some plants are transplanted. The area of ​​the aquatic plants accounts for about the area of ​​the cultivation pond. 1/3. The stocking density of broodstock should be appropriate. Usually, from September to October, the broodstock chosen for retirement should be stocked with 100 kg to 150 kg per mu, and the broodstock selected for selection from March to April should be stocked with 80 kg to 100 kg per mu. Bathe the shrimp body with 3% saline for 10 minutes before stocking. During the cultivation, we must strengthen the feeding of feed, feed fresh water grass, bean cake, wheat bran or compound feed, and add a part of animal feed, such as chopped snail meat, livestock and poultry slaughtered leftovers. The daily feeding amount in March is 2%-3% of the body weight of broodstock, 4%-5% in April, and 6%-8% in May, and it is fed once a day in the morning and evening. 70%. At the same time, we will strengthen water quality management and add water and drainage depending on the color, transparency and weather conditions. Generally change the water once every 10 days -15 days, each time changing the pool of 1/3. Every 20 cubic meters of water per cubic meter of water use quicklime 20 grams -25 grams of water Quanchiposa 1, in order to maintain good water quality and promote gonad gonad development. Breeding and Incubation From April to May, when the water temperature reaches 18°C ​​or more, broodstock begin mating. At the time of mating, the males discharge the sperm into the female seminal vesicles and save it before spawning. The fertilized eggs were hatched as juvenile shrimps on the bristles of the female's abdomen's appendage, and the incubation temperature was 22°C-28°C. When the water temperature is 18°C-20°C, the incubation period is 30 days-40 days; when the water temperature is 25°C, it only takes 15 days-20 days. When a large number of juvenile shrimps are found in breeding ponds, they should be picked in time. The seedling cultivation seedling ponds are preferably made of cement ponds of 20 to 40 square meters and water depths of 0.6 to 0.8 meters, but also soil ponds with an area of ​​1 to 3 acres, a slope ratio of 1:2, and a water depth of 0.5 to 1 meter. The water source must be sufficient, the water quality is good, and the water intake and drainage are convenient. The facilities for preventing escape are better. The stocking rate for juvenile shrimp is generally 150 to 230 tails per square meter.
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Five measures of artificial propagation of crayfish fry