1.常见病害的发病原因(1)水环境污染育苗水体因过量投饵或换水量不足,残饵及代谢产物积累引起富营养化。(2)亲体或幼体质量差亲体质量差,或在亲体培养促熟过程中,加温过快,环境因子突变,培育水温过高等导致孵化后的幼体先天不足。(3)病原体入侵育苗用水及育苗设施、工具处理不 1. The causes of common diseases (1) water pollution water body due to excessive feeding or water for lack of bait and metabolite accumulation caused eutrophication. (2) poor quality of parental or juvenile poor parental quality, or in the process of prokaryotic growth and ripening, warming too fast, mutation of environmental factors, breeding water temperature is too high, leading to hatchling larvae after birth deficiencies. (3) pathogen invade seedling water and nursery facilities, tools do not handle