一、发病症状及特点病鱼鱼体发黑,消瘦,大多离群独游于水面、岸边或下风口处。投饵时不吃料。剖开腹部,肝脏呈土黄色,颜色变淡或苍白,呈花斑状。用手捏易碎,放入水中易散开。肝囊肿大,胆壁变薄,胆汁呈墨绿色,肠道内无食或少食。病鱼反应迟钝,离水后不久便死亡。该病一般多发于5～7月,7月份为发病高峰期,以个体体重50～250克的发病率较高。 First, the incidence of symptoms and characteristics of diseased fish black, thin, mostly outlier swimming in the water, the shore or the next at the outlet. Do not eat when feeding material. Cut open the abdomen, the liver was khaki, pale color or pale, was a flower-like. Fragile by hand, easy to spread into the water. Liver cysts, gallbladder wall thinning, bile was dark green, no food or eat less in the intestine. The sick fish reacted unresponsively and died shortly after leaving the water. The disease usually occurs in May to July, the peak incidence in July, with an individual body weight of 50 to 250 grams of higher incidence.