中文摘要：

2009年4月至2012年7月，对额尔齐斯河（中国段）湖拟鲤（Rutilus rutilus lacustris Pallas）鳃部寄生的指环虫（Dactylogyrus）进行了取样调查，以期了解湖拟鲤寄生指环虫的种群生态学特点。结果表明，湖拟鲤共感染了2种指环虫，分别为维氏指环虫（Dactylogyrus vistulae Prost）和双髻指环虫（Dactylogyrus sphyra Linstow ），总感染率为22．22％，平均感染强度为4．5（1～24）；平均感染强度在16＜L≤19范围内达到最大，而19＜L的体长组感染率及感染强度同时达到最低，在不同体长组宿主中指环虫种群的分布类型除19＜ L为均匀分布外其余均为聚集分布，各体长组宿主的感染强度中19＜L与10＜L≤13、3＜L≤16和16＜L≤19三个体长组之间差异显著（P＜0．05），其余体长组之间的感染强度差异均不显著（P＞0．05）。

英文摘要：

This paper revealed the population dynamics of Dactylogyrus by field sampling investigation from April 2009 to July 2012 in Irtysh River .Dactylogyrus was found in the gills of Rutilus rutilus lacustris .The results showed that two Dactylogyrus species infected Rutilus rutilus lacustris including Dactylogyrus vistulae and Dactylogyrus sphyra , and their infection rate was 22 .22% and mean infection intensity was 4 .5（1-24） .The average intensity in the 16〈L≤19 was most ;the prevalence and intensity of 19〈L reached the lowest at the same time ,The 19〈L was uniform distribution and other groups of body length host are aggregated distribution in the population distribution type of Dactylogyrus,the19〈Landotherthreelengthgroups（10〈L≤13,13〈L≤16,16〈L≤19）weresignificantdiffer-ence respectively ,the remaining differences were not significant .