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加强河蟹越冬期管理,主要抓好以下几点。 1.成熟小蟹不宜越冬 有些小蟹虽然体重只有20克左右,但生长期已有2年之久,性腺发育已经成熟,体内渗透压升高,不能适应淡水的低渗透压,脱壳困难,最终死亡。因此,凡成熟的小蟹不能越冬,这种小蟹判断方法是:①外壳呈墨绿色;②雄蟹螯足绒毛粗长,雌蟹肚脐成椭圆形,边缘有短而密的黑色绒毛。
Strengthen crab overwintering management, mainly do a good job the following points. 1. Mature crabs should not overwinter Although some crabs weighing only about 20 grams, but the growth period has been 2 years, the gonadal development has matured, the body increased osmotic pressure, can not adapt to the low osmotic pressure of fresh water, shelling difficult, Eventually die. Therefore, all mature crabs can not wintering, this small crabs determine the method is: ① shell was dark green; ② male crab foot fluffy long, female crab navel oval, the edge of the short and dense black fluff.