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河蟹在生长过程中经过多次蜕皮,如果性成熟过早,河蟹就不再蜕皮生长,达不到商品规格而过早死亡。因此在河蟹养殖过程中必须十分注意河蟹的性早熟问题,据分析应注意以下几点:1 盐度 我们对昌黎县内几个养蟹户进行调查发现,沿海的几个坑塘河蟹性成熟过早,有的体重只有20～25g就已达性成熟,不再蜕皮生长,并大批死亡。性早熟的蟹体色为墨绿色,雄性腹脐无变化,雌性脐部变成圆脐,成熟系数达1.5％。而我县远离海边的坑塘并未出现性早熟现象并且产量很高。针对这种
Crabs in the growth process after many molting, if sexual maturity, crabs no longer molting growth, reach the product specifications and premature death. Therefore, in the crab breeding process must pay great attention to the problem of precocious crab, according to the analysis should note the following: 1 salinity we Changli County, several crab households found that several pit ponds crab coastal maturity Early, some weight only 20 ~ 25g has reached sexual maturity, no molting growth, and a large number of deaths. Sexual precocious crab body color is dark green, no changes in the male belly button umbilical, umbilical into a navel, maturity factor of 1.5%. And my county far away from the beach Pit does not appear precocious puberty and high yield. For this