河南省处于我国北方地区,精养渔业发展很快,集约化程度较高,但养殖密度不断增加,养鱼带来的高效益使人们高频率地使用鱼池而减少或根本不清整池塘,加上鱼苗鱼种的频繁交换,鱼病发生越来越多,危害越来越大。特别是近几年细菌出血性败血病 Henan is located in the northern part of our country. The development of intensive fisheries has been developing rapidly with a high degree of intensification. However, the breeding density is continuously increasing. The high benefits brought by fish farming make it possible to reduce or eliminate the ponds at high frequency using fish ponds. Frequent fish seedlings exchange, more and more fish diseases, more and more harmful. In particular, bacterial hemorrhagic septicemia in recent years