First, grading and raising.
After long-distance transportation of juvenile crabs to the pond, the first time the clam shells were damaged (local crabs did not exist in this situation). For ease of management, juvenile crabs must be grading and grading. "Glyph's child pool or "day" font cascade pool. The stocking density is 2000-5000/mu, and the stocking is in line with the growth pattern of crabs, which facilitates the feeding and management of juvenile crabs, and facilitates the growth of crabgrass plants during the cultivation of juvenile crabs. In addition, it is convenient for “numbering†after May.
Secondary breeding can timely supplement the seed (in the first-level culture pool in the ground cage "after" into the crab breeding pond, the general secondary stocking density is between 500-800 per mu). Otherwise, it is very difficult to control the survival rate of juvenile crabs in big pools, and the economic benefits are often caused by insufficient seed stocks.
Second, scientific feeding.
Juvenile crabs have significantly increased food intake compared with crab seedlings, and have a wide range of feeds. The proportion of animal and plant feedstuffs is appropriate from 1:2 to 2:3. Full-price pelleted feed is recommended. Single feed will be prone to nutrient deficiency due to incomplete nutrition, on the other hand, it will easily pollute the water and cause disease. The amount of feeding will be 5-10% of the body weight of crabs, and will increase or decrease according to the situation of eating and drinking in the evening. When feeding, spread along the shallows around the pool. If a large number of shells are found in the crabs, they should be far away from the grass or crabs and shells to avoid feeding each other.
Third, daily management.
In the first-level cultivation pond, because the aquatic plants have not yet grown well, it is now possible to go to the river or lake area to retrieve the freshly-frozen water plants and put them into the pool, and put the snails in appropriate amounts to supplement the natural and cheap feed of the crabs, but whether they are aquatic grasses or snails, It must be sterilized prior to release to prevent bacteria or harmful substances from entering the cultivation pond. During the young crabs, the water level should be shallow and be kept at 30-50 cm. If the water level is too deep, the water pressure will be high, which is not conducive to the growth and shelling of juvenile crabs. The pH value of juvenile crabs should be between 7.5-8.5. To be comprehensive nutrition, it is best to feed the full price pellets, if it is artificial feed, regular supplements of antibiotics, dehulling, calcium dihydrogen phosphate and other substances to meet the growth needs of crabs. Each day, the crab ponds were patrolled several times to observe the habitat and feeding conditions of the river crabs, check the escape prevention facilities, and promptly repaired the problems to prevent the crabs from escaping, regularly measure the water quality, carry out water quality improvement, and severely guard against sudden weather changes.
In short, the healthy breeding of crabs must have: a foundation that is an excellent aquaculture water environment; three elements namely water, species, bait; a core that is scientific management technology. To achieve the above points, we can ensure the healthy growth of crabs and increase the economic benefits of farmers.
The crabs are one of the aquaculture species developed in recent years. Many farmers raise their crabs in the breeding process according to their traditional fish farming experience, but the yield is not high. Together with the low market price and serious disease, many farmers Losses year after year. The author discussed some of the shallow views on the scientific breeding and management of common crabs in the current production practice for the majority of farmers to refer to in production practice.