2. Quality requirements: After metamorphosis to C4 stage, most of the young crabs in artificially cultivated fry are below 5000 /kg, with hard and blue shell, neat specifications, complete appendages, no damage, sensitive response and strong vitality, and the shell width is 65438 00 mm. ..
3. The fry should choose the blue crab from Zhejiang, especially Sanmenwan, which has the distinctive characteristics of "golden claws, green back and yellow belly", fresh and tender meat, delicious taste and slightly sweet taste. The crab seedling pliers are plump, red and oval, and the carapace is green and shiny. However, Guangdong, Fujian and other southern green crab seedlings have long claws, dark red and rectangular tips, and their shells lack luster and spots. On the one hand, southern green crab seedlings are not suitable for breeding in Jiangsu and Zhejiang provinces, especially in winter, there will be a series of problems, such as not being able to overwinter normally; On the other hand, the quality of this crab is not as good as that of Zhejiang local blue crab.
4. Before stocking, the seeds must be soaked in strict drugs to kill the germs on the body surface. Larvae can be soaked in 5 g/m3 potassium permanganate solution for 15 minutes, or in pure fresh water for 15 ~ 30 minutes. The stocking density of blue crabs in this farm is controlled at 4.5 individuals /m2.