Crayfish breeding technology
1. Breeding site selection and engineering construction
（1）Crayfish breeding sites require adequate water sources, convenient irrigation and drainage, and strong flood and drought resistance capabilities. The pH value of the soil is neutral to slightly alkaline, and there is plenty of sunlight and long exposure time, which is conducive to the reproduction of plankton, especially leeward to the sun. In order to ensure that crayfish products meet the pollution-free requirements, the breeding site must be far away from industrial, agricultural and domestic pollution sources, and the environment must meet the pollution-free breeding standards.
（2） Reinforce and heighten the ridges, and excavate shrimp trenches and shrimp pits. In order to prevent the crayfish from punching through the ridge when digging holes, causing the ridge to collapse; after heavy rains in the flood season, it is easy to cause flooding shrimp, so it is necessary to increase the height, widen and compact the ridge. The reinforced ridge should be 40-50 cm above the water surface, and the base of the ridge should be widened to 80-100 cm. Use window screen mesh or calcium plastic board to build an escape wall around the ridge, 70-80 cm above the ridge.
Use wooden stakes or bamboo poles to support and fix them every 1.5 meters. In the upper part of the mesh, an agricultural film with a width of about 30 cm is sewn to form an "upside down whisker" to prevent the crayfish from climbing and burrowing to escape. Excavate shrimp pits along the ridge around the field to create a good living environment for crayfish and facilitate centralized shrimp catching. The shrimp pit is about 1 meter deep and about 1 meter wide.
2. Daily management of breeding
（1） Fertilization and disinfection. Base fertilizer should be used as the main fertilizer, preferably organic fertilizer. When using base fertilizer, apply 150-200 kg organic fertilizer per mu. 10-15 days before stocking shrimp larvae, shrimp ditch and shrimp pit should be disinfected. Use 100-150 kilograms of quicklime per mu, and splash it with water.
（2）Shrimp species stocking. There are two ways of stocking: one is to put broodstock to reproduce on their own, usually from the end of August to mid-October. The stocking size of crayfish per acre is about 20 kg per kg. The other is stocking juvenile shrimp in spring. There are 25,000 to 45,000 crayfish juveniles with a size of 250 to 600 per kilogram per mu. Shrimp body disinfection should be carried out when stocking, and the shrimp species can be soaked in a salt solution with a concentration of about 30% for 3 to 5 minutes.
(3) Feeding of crayfish feed. Crayfish feed includes rice bran, bean cake, bran, trash fish, snail meat, silkworm pupae, earthworms, slaughterhouse scraps or compound feed. The feeding amount is determined by the amount of natural food in the lotus root field and the stocking density of crayfish. During the whole season of feeding, follow the principle of "starting early, having less at the beginning, more in the middle, and less in the later period". The water temperature is suitable from June to September, which is the peak growth period of crayfish.
Generally, they are fed 2 to 3 times a day, at 9 to 10 in the morning and around sunset or at night. The daily feeding amount is 5% to 8% of the shrimp body weight. In the rest of the season, it can be fed once a day, around sunset, and the daily feeding amount is 1% to 3% of the shrimp body weight. The bait should be put in the area close to the shrimp ditch and shrimp pond, shallow water level and concentrated crayfish, in order to facilitate its feeding and check the eating situation.
(4) Disease control. Use quicklime to disinfect once every 15-20 days in high temperature season, 10-15 kilograms per mu each time, add a certain amount of allicin, multivitamins and other drugs to the feed, which can generally control the disease.
(5) Fishing. Crayfish fishing mainly uses ground cage nets, which can be caught all year round, with large catches and small catches. The main fishing period is April to September. If each time the catch is very small, the fishing can be stopped.
3.Matters needing attention
（1）How to understand the abundance of water resources? People in hilly areas are often overly arrogant and confident about their understanding of water resources. Many places where there is no water source are not suitable for aquaculture. Farmers think they have enough well water and blindly build them. As a result, they are deserted in the second year at most the third year. You must know that aquatic products such as crayfish must be kept in large quantities at any time when the water is most scarce. After a few hours, it may be wiped out.
（2）The problem of introduction. At present, there are relatively small differences in species in crayfish farming, and the focus is to ensure the survival rate of the first week of introduction.
（3）The management personnel must have the advantages of enduring hardship and learning, and be able to be diligent and meticulous for a long time, learning and summarizing the ability to improve their own level.