What to pay attention to when raising crayfish through the summer

First, make good preparations before stocking: the pond must have good water inlet and drainage facilities. Around the pond, use bamboo strips, mesh gauze, etc. to enclose an anti-escape wall 50 cm high.  

Set up shrimp habitat sites in the breeding water area, such as installing tiles, bricks, stones, mesh sheets, old tires, grass ropes, etc. as shrimp nests, for the shrimp to hide and rest and defend against enemies. 

Plant aquatic plants such as water hyacinth, alligator weed, water lettuce, and wild rice stem around the pond, with coverage generally 1/3 of the pond water surface, to help shade the crayfish and encourage the growth of plankton that crayfish like to eat.  

Generally, for newly built crayfish ponds, quicklime water can be used to clear the pond with water present, using 100 kg per mu. If using old ponds or lakes to raise crayfish, clear silt, repair, and sun-dry them. 10~15 days before stocking shrimp fry, use 50 kg of quicklime per mu for dry pond disinfection. At the same time, thoroughly eliminate predatory wild enemies in the pond such as catfish, loach, snakehead, snakes, and rats.  

10~15 days before stocking shrimp fry, generally apply pig manure and fermented manure at 00~200 kg per mu of water surface to cultivate plankton and provide an appropriate amount of organic debris as shrimp feed.  

Before water is let into the pond, install the water screen, preferably 60~80 mesh, to prevent enemies in the water from entering. Keep the pond water depth at 50~80 cm, with transparency between 30~40 cm.  

Second, stock shrimp fry: stocking shrimp fry is best done on sunny mornings and evenings, stocking 6000~8000 young shrimp 2 cm long per mu or 4000~6000 young shrimp 3~5 cm long. The shrimp fry stocked in the same pond should be required to be uniform and consistent in size. At the same time, about 50 g silver carp and bighead carp can be stocked in the pond water at 300~400 fish, and 200 bream.  

Third, feed carefully: within 3 days after releasing the fry, feed minced small fish and minced meat. From 3 days to 1 month afterward, feed small miscellaneous fish, scrap minced meat, or compound feed. When the shrimp fry grow to 6~7 cm, all can be fed crushed snails, river mussels, and an appropriate amount of plant-based feed such as wheat, bran, corn, cake meal, etc., or compound feed. The daily feeding amount should be based on eating well, finishing the food, and leaving no residual bait. Generally, for medium and small crayfish, feed 15%~20% of body weight, and for adult shrimp feed 5%~10% of body weight. The specifics can be adjusted according to the shrimp's feeding situation. Feed twice a day, once in the morning and once in the evening. The evening feeding amount accounts for 70%~80% of the daily feeding amount. The bait should be placed around the pond and properly scattered. Where crayfish are concentrated, put a little more to help them feed.  

Fourth, water quality management: crayfish grow quickly, have vigorous metabolism, and consume a lot of oxygen, so the shrimp pond water quality must remain fresh. Add water 15~20 cm deep each week to ensure the water quality is fresh, clean, and has enough dissolved oxygen. Keep pond water transparency above 35 cm deep. When the weather is too hot, properly deepen the pond water to stabilize the pond water temperature. Strictly prevent water quality from being polluted by industrial pollution, pesticide pollution, and chemical pollution.  

When dissolved oxygen in the water is low, water quality is aging, or in severe weather such as thunderstorms, muggy days, and consecutive cloudy days, reduce the feeding amount or stop feeding, and pay attention to observation. If crayfish are found to react slowly, gather by the shore, float at the surface, and climb onto the bank, it indicates severe oxygen deficiency, and water should be added promptly or an aerator turned on to increase oxygen.  

Fifth, prevent disease: check frequently and patrol the pond frequently, paying attention to the crayfish's foraging, activity, growth, and molting, so that necessary technical measures can be taken promptly. Promptly remove moss from the pond; often check the filter screens at the water inlet and outlet to prevent crayfish from escaping or harmful organisms such as wild miscellaneous fish from entering due to damaged filter screens. Always pay attention to whether there are harmful organisms in the pond, such as water rats, water snakes, water birds, frogs, and harmful fish, and remove them promptly if present.  

Before the shrimp fry are put into the pond, disinfect their body surface to prevent bringing pathogens into the pond. Regularly disinfect the shrimp pond with quicklime, often add fresh water, keep the pond water clean and sanitary, and add multiple vitamins to the shrimp feed to enhance the shrimp's immunity.  

Sixth, harvest in a timely manner: generally after about 2 months of rearing, when crayfish reach more than 50 g in body weight, they can be harvested for market. Harvest crayfish using methods such as shrimp cages, ground cages, and surround nets, catching the large and keeping the small.