Freshwater crabs are mainly Eriocheir sinensis in the Yangtze River system, and the world-famous Yangcheng Lake hairy crabs are of this type, which are characterized by white abdomen, yellow back, strong claws, long legs, prominent eyes and hairy claws. How can we cultivate crabs in fresh water? Let's introduce the breeding technology:
1, the pond for raising crabs requires a pond with good water quality and convenient irrigation and drainage. The area should be large and not small, and it should be between 5 10 mu and the water depth should be 1 12 meters. The mud pad in the pond should be shallow but not thick. An escape fence should be installed at the inlet and outlet, and an escape net should be installed around it or a brick wall should be built (the wall height is 50 100 cm). At the same time, the quality of escape prevention facilities is related to the success or failure of aquaculture in the range of 40 cm from the highest water level of the pool water, such as plastic plates, glass and polyethylene films. Eriocheir sinensis is a crustacean. After it grows for a certain period of time, it gradually grows by shelling again and again. Therefore, it is necessary to plant aquatic plants and other hidden places for Eriocheir sinensis in the pond.
2. The stocking specifications and density of crab seedlings are related to the production cycle. When young crabs (each weighing 3-4g, about 300 per kilogram) can be put in 2,000-3,000 per mu, and small crabs can be put in 1000 every other year, after adult crabs that can meet the commercial specifications are cultivated, some mild filter-feeding fish can be mixed in the crab pond, such as \.
3. There are a wide range of bait sources for feeding management crabs. Except all kinds of aquatic plants, fresh crop straws, agricultural products, snails, animal leftovers, fish and shrimp can be fed. When feeding, it can be carried out according to the following proportions: animal bait accounts for 35%, plant bait accounts for 30%, green feed accounts for 35%, and edible salt of 1-2% is added to improve the feeding intensity and utilization rate of river crabs. Feeding is carried out according to the "four determinations" in aquaculture methods. The feeding frequency can be once a day in May1October when the water temperature is high, and once every 213 days in early spring and late autumn. The feeding time should be chosen in the evening, and the feeding point should be chosen on the slope near the water in the west bank of the pond. Special note: When feeding bait in September 10, calcium content should be added to the bait in advance, which is beneficial to speed up the shelling and long shell growth.
4. Water quality requirements and disease prevention Eriocheir sinensis requires high water quality, the oxygen content is above 4 mg/L, and the PH value is between 7.5 and 8.5. The water in the pond should be controlled at a depth of 50-60 cm when the seeds are first released, and then gradually deepened to 1.2-1/.4 m, and it will take 1-2 weeks to change/kloc. During the feeding process, it is necessary to regularly patrol the pond to check whether the escape prevention facilities are damaged or damaged by enemies, and regularly sprinkle bleaching powder into the pond water in peacetime to prevent diseases.