Crab seedlings should be selected for 6 days or more, desalinated for more than 4 days, and have a salinity of 3 or less; a strong physique, a hard crust, strong vitality, and golden yellow; the individual size is uniform, and the specification is 18104/kg.
Crab crabs should be transported with a layer of gauze, towels or grass before transporting the crabs. This will not only keep them moist, but also prevent the local water and seedlings from having different thicknesses. After the crabs are weighed, gently spread them evenly in the tank. In the process of transporting seedlings, to prevent wind blow, sun exposure, rain and prevent excessive temperature or dry water shortage, it is also necessary to prevent excessive watering and local oxygen deficiency.
Crab stocking stocking density 1000 / square meter. When releasing the seedlings, first place the crab seedlings in the pond, splash the pond water, and then put the box into the pond. Let the crab slowly and automatically spread out and walk. Don't fall down.
After the feed is fed to the lower pool of crabs, the plankton in the pool is used as bait for the first three days. If the natural food in the pool is insufficient, plankton can be harvested or artificial feed can be added until the first oyster shell is turned into the first stage crab. After the first phase of larval crabs, the fresh fish larvae were fed with fresh porcine blood and tofu soup. The daily feeding amount was approximately 100% of the body weight of the crabs. Feeding was performed 6 times a day until the third larvae appeared. The third period of daily supply of crabs was about 50% of the body weight of the crabs, and they were fed three times a day until they became four. After this, the amount fed was reduced to less than 20% of the body weight of the crab, and the duckweed was fed at the same time until 4 weeks after the seedling was injected, and the method of feeding was evenly sprayed on the whole pool.
When water quality controls crab seedlings, the water level is maintained at 60-80 cm, and no water is added for the first three days. After the first phase of crabs, the newly filtered water is gradually added. After the water depth reaches 100 cm, the water is changed, and the water is discharged first. The daily water exchange volume is usually 1/4 or 1/3 of the cultivation pond water. Every 5 days, lime water was splashed into the cultivation pond and the pH of the pool water was adjusted between 7.5-8.
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