鱼类在发病前是有一定先兆的,养殖者可以根据鱼的活动、摄食、体色和水质变化等情况来判断鱼类是否有病。——观察活动情况。健康的鱼游动活泼,常结伴集群而游,反应十分灵敏,一有惊动就迅速潜入水底。病鱼则离群独游,游动缓慢无力,时 Fish before the onset is a certain precursor, farmers can fish according to activity, feeding, body color and water quality changes to determine whether the fish sick. - observe the activity. Healthy fish swimming lively, often with the cluster and swim, the reaction is very sensitive, as soon as the alarm quickly sneaked into the water. Diseased fish are outlier solitary tour, swimming slow and weak, when