2004年5月20日至6月底,我省沿海普遍发生了养殖异育银鲫大批死亡的现象,2005年同期又有暴发,其发病率明显提高,发病程度也比上年严重,2004年发病塘口比例约占10%,2005年粗略估计发病塘口比例约占30%以上。目前发病严重的,一般200亩左右的塘口,日死鱼量高的已达1000千克以上,累 From May 20 to the end of June 2004, a large number of deaths of aquaculture silver carp were widespread in the coastal areas of our province. In the same period in 2005, there were outbreaks which significantly increased the incidence and severity of the disease more than the previous year. In 2004, Tongkou proportion accounts for about 10%, in 2005 a rough estimate of the incidence of pond proportion accounts for about 30%. The current incidence of serious, generally about 200 acres of Tangkou, the amount of dead fish has reached more than 1,000 kg, tired