春季气温逐渐回升,一般温度在10～20℃之间,水温比较适宜各种病源体生长繁殖,尤其4～5月份更是鱼类发病的高峰季节。早春鱼苗孵化时,鱼卵易患水霉病,鱼苗易患指环虫、小瓜虫、斜管虫等鱼病。其症状及防治方法如下: 1.水霉病。病鱼体表水霉菌丝大量 Spring temperatures gradually picked up, the general temperature between 10 ~ 20 ℃, the water temperature is more suitable for a variety of growth and reproduction of the source of pathogens, especially from April to May is the peak season of fish incidence. Early spring fry hatch, the fish susceptible to watery mildew, fry susceptible to finger worm, small melon worm, pipefish and other fish diseases. The symptoms and prevention methods are as follows: 1. Water mold disease. Disease fish surface water mycelium a lot