First, the conditions of the waters The water area requires a flat bottom, a micro-flow, submerged plants flourishing, rich benthic animals, fresh water, environmental stability, the normal water level between 80-150 cm.
2. There are two types of network perimeter facility construction and scale network perimeter settings: (1) If it is set within the crab net perimeter, it is a single-layer network structure; (2) a separate, double-layer network structure. The line-up mesh uses a 0.3-cm meshless network. The outside of the net perimeter is fixed with bamboo piles, the bottom is covered with mud in the gabion, and the upper end is erected to prevent the facilities, and the height is about 2.5 meters. If it is set separately, a layer of protection network is set up on the periphery. The scale of dunking crab nets needs to be matched with adult crab breeding, which is usually about 1:20 in the trade.
3. Preparation before stocking 1. Clearing and destroying the wild: Before the juvenile crabs are stocked, use a cage and a wire mesh to completely remove the wild fish in the net enclosure to reduce the attack on the river crab by the enemy and improve the crabs. Survival rate. 2. Renovation and cultivation of natural feed organisms: In the spring, we will focus on the transplantation, cultivation and protection of aquatic plants to ensure a good marine pollutant environment. At the same time, before April, the number of snails laid per mu should not be less than 200 kg.
Fourth, juvenile crab stocking 1, stocking time: should be based on different waters to relax the water cut off the water to drain more people, generally should be stocking from June to August. 2. Quality requirements for juvenile crabs: Juvenile crabs are required to be seedlings of the Yangtze River water system, with neat specifications, strong ability to move, no injuries, and no sickness. The appendages are complete. Small-sized juvenile crabs have a strong swimming ability, and they easily escape during the flood season. Therefore, the appropriate stocking size is 1500/kg. 3, the amount of stocking: stocking should be based on the natural resources of the water resources to determine the state, generally controlled at 15,000/mu.
5. Feed Feeding During the cultivation of crab species, fresh waterweed is the main supplement, and the daily feeding amount is 40%-60% of the crab's body weight. At the end of September and early October, appropriate artificial diets can be added. The daily feeding amount is 3%-5% of the body weight of the crabs to increase the nutrient accumulation in the crabs, enhance the body composition of crabs, and increase the survival rate of overwintering.
VI. Daily management 1. Adhere to the morning and evening patrols: During the day, the main observations are water temperature and water quality changes. During the evening and night, the river crab activities and eating conditions are mainly observed so that management measures can be adjusted in time. 2. Mesh care: Regularly check, repair and reinforce the net enclosure facilities. In particular, during the flood season and typhoon season, it is necessary to step up patrol inspections, timely increase the height of the facilities, and find that problems are resolved in time to prevent crabs from escaping. 3, to strengthen the care of soft shell crab: crab shelling during the peak period, to give paternal food, provide a good hidden environment to reduce the self-inflicted. 4. Keep the environment clean and tidy: timely clean up the residue and debris of aquatic plants in the enclosure to keep the environment clean.
VII. Disease Prevention 1. Every 10 days or so, splash lime with 10 mg/liter of lime to improve the water environment and adjust the pH. 2. Ensure the quality of feed, scientific and scientific feeding, prevent the impact on the river crab and the environment due to water leveling and bait rotting.
(Jiangsu Wujiang Fisheries Technology Promotion Station Bao Junjie 215200 Miaogang Town Agricultural Service Center Shi Xiaxin 215232)
2. There are two types of network perimeter facility construction and scale network perimeter settings: (1) If it is set within the crab net perimeter, it is a single-layer network structure; (2) a separate, double-layer network structure. The line-up mesh uses a 0.3-cm meshless network. The outside of the net perimeter is fixed with bamboo piles, the bottom is covered with mud in the gabion, and the upper end is erected to prevent the facilities, and the height is about 2.5 meters. If it is set separately, a layer of protection network is set up on the periphery. The scale of dunking crab nets needs to be matched with adult crab breeding, which is usually about 1:20 in the trade.
3. Preparation before stocking 1. Clearing and destroying the wild: Before the juvenile crabs are stocked, use a cage and a wire mesh to completely remove the wild fish in the net enclosure to reduce the attack on the river crab by the enemy and improve the crabs. Survival rate. 2. Renovation and cultivation of natural feed organisms: In the spring, we will focus on the transplantation, cultivation and protection of aquatic plants to ensure a good marine pollutant environment. At the same time, before April, the number of snails laid per mu should not be less than 200 kg.
Fourth, juvenile crab stocking 1, stocking time: should be based on different waters to relax the water cut off the water to drain more people, generally should be stocking from June to August. 2. Quality requirements for juvenile crabs: Juvenile crabs are required to be seedlings of the Yangtze River water system, with neat specifications, strong ability to move, no injuries, and no sickness. The appendages are complete. Small-sized juvenile crabs have a strong swimming ability, and they easily escape during the flood season. Therefore, the appropriate stocking size is 1500/kg. 3, the amount of stocking: stocking should be based on the natural resources of the water resources to determine the state, generally controlled at 15,000/mu.
5. Feed Feeding During the cultivation of crab species, fresh waterweed is the main supplement, and the daily feeding amount is 40%-60% of the crab's body weight. At the end of September and early October, appropriate artificial diets can be added. The daily feeding amount is 3%-5% of the body weight of the crabs to increase the nutrient accumulation in the crabs, enhance the body composition of crabs, and increase the survival rate of overwintering.
VI. Daily management 1. Adhere to the morning and evening patrols: During the day, the main observations are water temperature and water quality changes. During the evening and night, the river crab activities and eating conditions are mainly observed so that management measures can be adjusted in time. 2. Mesh care: Regularly check, repair and reinforce the net enclosure facilities. In particular, during the flood season and typhoon season, it is necessary to step up patrol inspections, timely increase the height of the facilities, and find that problems are resolved in time to prevent crabs from escaping. 3, to strengthen the care of soft shell crab: crab shelling during the peak period, to give paternal food, provide a good hidden environment to reduce the self-inflicted. 4. Keep the environment clean and tidy: timely clean up the residue and debris of aquatic plants in the enclosure to keep the environment clean.
VII. Disease Prevention 1. Every 10 days or so, splash lime with 10 mg/liter of lime to improve the water environment and adjust the pH. 2. Ensure the quality of feed, scientific and scientific feeding, prevent the impact on the river crab and the environment due to water leveling and bait rotting.
(Jiangsu Wujiang Fisheries Technology Promotion Station Bao Junjie 215200 Miaogang Town Agricultural Service Center Shi Xiaxin 215232)