Mixed Culture technique of River Crab and Green Shrimp

1. Pond conditions. Pond area of 3-8 mu is appropriate, abundant water, fresh water quality, no pollution; equipped with aerator or water pump and other fishery machinery; inlet and outlet installation of anti-escape net. The pond is cleaned in winter and thoroughly sterilized with 100-150 kg of quicklime per mu. 2. Snail is recommended. Planting aquatic plants in ponds before and after the Spring Festival requires a coverage rate of 60-70% in summer, and 300-400 kg of sterilized snails per mu. 3. Seedling stocking. The release time of green shrimp is from December to February of the following year, and the release time of crab species is from December to February of the following year. The release time of crab species is from February to March, with 120,160ind / kg per mu, 600,700eggs per mu, and the fry of green shrimp is released in the first and middle of July, with specifications of 1000 / kg and 50,000 to 70,000 per mu. Seedlings are required to be disease-free and injury-free, and should be released after disinfection. 4. Feed. Feed feeding follows the principle of "essence at both ends, coarse in the middle", "the combination of meat and meat, and the combination of green and essence". At the same time, it can be flexibly controlled according to the weather, water temperature, water quality and the feeding of farmed varieties. Feeding protein content is required to be more than 35%. 5. Water quality regulation. Add new water or change water regularly or irregularly; sprinkle with raw calcareous slurry in the whole pool every 15-20 days; sprinkle regularly with biological agents and water in the whole pool; keep the transparency of the pool water at 30-40 cm. 6. Disease control. In accordance with the principle of "giving priority to prevention and combining prevention with prevention", the use of prohibited drugs is strictly prohibited. 7. Daily management. Patrol the pond every morning and evening, mainly observe the changes of water color, the activities of breeding varieties, eating, shelling, inspect the table, remove residual bait or dirt in time, prevent water quality deterioration, and make good records of daily management, feeding, water quality management, disease prevention and so on. 8. Fishing time. Spring shrimp fishing began in April, autumn shrimp fishing began in September, river crabs began timely fishing according to the market situation at the end of September, the implementation of the method of catching large and small. 9. The key to management. ⑴ should clear the pond thoroughly. ⑵ prawns and crabs do not use any fish medicine during shelling. ⑶ strictly prevents water plants from rotting in the hot season. ⑷ fishing in good time. 10. Benefit analysis. Generally, there are 80-90 kg of river crab and 50-60 kg of green shrimp per mu, with an output value of about 9000 yuan per mu, deducting 3500-4000 yuan per mu of production cost and 5000-5500 yuan per mu.