Crab breeding technology

The conditions for crab breeding ponds are: convenient transportation, quiet environment; abundant water supply, good water quality, no pollution, convenient irrigation and drainage; pool bottom formation, pool slope ratio 1:2.5-3. Anti-escape facilities: There are mainly three forms of cement brick walls, calcium-plastic plate fences, and polyethylene mesh fences. At present, calcium plastic fences are commonly used. The calcium-plastic composite plates are compacted 20 cm around the concrete in the earthen bowl and fixed at intervals of 1 m with wooden stakes. Sterilize the clear pond: Remove excess silt, leaving only about 10 cm of silt, splashing with quicklime, 200-250 kilograms per acre, to achieve thorough disinfection of clear ponds, to remove the wild, kill germs, improve the bottom Quality, 7 days after the drug, that is, over the water 1, to remove the dirt, and then add water after 3-5 days. The plants to be planted in crab ponds: To cultivate a pond crab, we must first plant a pond grass. Water plants are one of the natural foods that crabs love to eat, and they can also play a role in purifying water quality. It is also a habitat for crabs to escape from the enemy. Harmful place. The area of ​​aquatic weeds should account for more than 70% of the area of ​​ponds. The main species include black algae, Vallisneria, Elodea and so on. The black-leaf algae and Elodea species are mainly transplanted and cuttings are introduced, and the plants are planted by sowing. Crab ponds should be placed screws: Screws is one of the crabs like to eat natural food, but also to purify water. Before the stocking of crabs and the market and, put 300-500 kilograms of live screws per acre to cultivate the basic bait of crabs. The selection of crab species: Selection of species with neat specifications, complete appendages, disease-free, injury-free, quick-acting Yangtze River water species of Eriocheir sinensis is appropriate. Crab pond rational stocking: general crab species stocking to achieve "three suitable" and "a temporary raise", namely the appropriate density, timely stocking, moderate specifications and stocking after the first raise. The stocking density of crabs is generally about 500-600 per acre, so that crabs have ample space for life and growth. The time for stocking crabs is generally appropriate from the end of February to March of each year. Over winter, the number of casualties is heavier. When the water temperature rises too late, some crabs and clams will affect the survival rate of the lower pond. The stocking size of crab species should be 100-200 pieces per kilogram. The specification is too large. Every time the clam shell is difficult, the damage is heavier; if the specification is too small, the growth base is not large, which affects the market specification. The temporary conservation of crabs is a transitional phase before the stocking of crabs. It is necessary to first set up a “holding zone” in the pool. The length of the holding period should be determined by the water temperature and the growth of aquatic plants in the pond. The area is about 1/5 of the stocking area. Scientific and rational feeding materials: Crab is an omnivorous animal of partial animal feed. In the feeding of bait, strict implementation of the scientific method of "four determinations and four readings" and mastering the principles of "preliminary fineness, intermediate greenness, and meat quality matching". Feeding once in the morning and evening, the daily feeding amount generally accounts for 3-4% of crab body weight, and it is advisable to eat within 1-2 hours. In the initial stage of stocking, mainly animal feeds, mainly fresh fish, snail meat, etc., and then gradually increase the amount of vegetative concentrate feed, such as wheat, corn, soybean meal, etc., in high temperature season, do not cast For animal diets, less vegetable essence baits, and more crude fodder such as aquatic plants, pumpkins, potatoes, etc., enter the late stage of cultivation, for the river crab to promote growth and weight gain stage, it is necessary to increase the botanical concentrate feed and animal bait to ensure the crab Eat enough to eat. Crab pond water quality control: General water depth is maintained at 0.6-0.8 meters, adjusted to 1-1.2 meters in hot season. Water quality regulation focuses on three aspects: First, constantly changing new water, generally changing the water once every 7-10 days, when the high temperature water injection 10-20 centimeters per day, 3 days for water. The second is to adjust the pH of the water body, generally in the PH value between 7.5-8.5. The main use of quicklime adjustment, 7-10 days Quanchi pouring 1 time, the amount of water per acre per meter is about 10-15 kg. The third is to use photosynthetic bacteria to regulate the water quality, the amount of 3-5 kilograms per acre, the whole pool pouring water in order to transform the water in the ammonia, nitrogen, hydrogen sulfide and other harmful substances, control the breeding and breeding of harmful bacteria. Crab fishing: Generally entered in October, according to the temperature and market conditions, timely fishing listed, the main tool is the ground cage.

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