Three key measures for artificial Culture of River Crab

Artificial breeding of river crab is the key in the production process of river crab. Only when this link is grasped well can we provide a large quantity and good quality of crab seedlings and lay a foundation for the whole breeding process.

First, the preparatory work in the early stage of raising seedlings 1. Washing and disinfection of the seedling pond: the seedling pond should be thoroughly washed and disinfected 3 ~ 5 days before the larva discharge, and the newly built seedling pond should be soaked one month in advance. Disinfect every cubic meter with 100 grams of chlorine king, then rinse with sterilized sea water and set aside. two。 Water injection: after the toxicity of residual chlorine disappears, the sterilized seawater can be filtered and injected into use. 3. Live food culture: River crab larvae and big eye larvae are omnivorous, especially like active bait, so it is very important to cultivate open food of river crab. ① botanical live food commonly used in the breeding production of river crab are unicellular algae such as Phaeodactylum tricornutum, flat algae and Chlorella, among which Chlorella is the best, but Chlorella culture needs more manpower and material resources and is not easy to culture. In order to solve this problem, "Shenyang" Company selected excellent foreign algae species, used modern biotechnology and advanced culture methods to produce pure natural Chlorella powder and concentrated Chlorella liquid, which solved the problem of open bait in the process of raising seedlings. The concentrated Chlorella solution can be directly put into the seedling pond, or it can be inoculated and cultured. After feeding, it was proved that it could promote the growth and development of larvae and significantly improve the survival rate. ② animal feed river crab likes to feed on rotifer, Artemia, Cladocera, copepod and so on at the stage of larval and bigeye larvae, and can artificially hatch the abundant eggs and cultivate them into larvae for feeding. In order to cut off this route of transmission, Crab'an No. 2 can be used to disinfect, sterilize and kill Polycondensate. Second, the cultivation of larvae includes artificial feeding, regulation of water temperature and water quality, aeration and strengthening management, prevention and control of diseases and insect pests, etc. The molting development of each stage has different requirements for the environment and bait, especially in the first stage, because of passive feeding, the density of feed particles fed in the seedling pond should always be kept above 100000 per milliliter. At the same time, in the prevention and control of diseases and insect pests should give priority to prevention, prevention and control should be combined. Third, the desalination of crab seedlings and out of the pond can be desalinated out of the pond after all the larvae have become bigeye larvae, and the fresh water sterilized by "chlorbao" can be gradually added to the breeding pond for about 4 ~ 5 days.