中文摘要：

利用分子生物学方法对采自额尔齐斯河（中国段）的白斑狗鱼（Esox lucius Linnaeus）晶状体内寄生的复口吸虫（Diplostomum）进行了种类鉴定，结果显示其种类为假尾复口吸虫（D.paracaudum），为中国新记录种。通过PCR扩增待鉴定种的部分18S-ITS1-5.8S序列，测序后与GenBank中假尾复口吸虫的序列进行比对，发现其相似度达到99.6%。将该序列与7种复口吸虫的ITS1序列进行比对后构建系统进化树，进化树以单殖吸虫Gyrodactylus parvae为外类群，结果显示：待鉴定种与假尾复口吸虫（D.paracaudum）聚为一支，其支持率达到了50%以上，支持它们为同一虫种。

英文摘要：

The current study identified a species of Diplostomum from the lens of Esox lucius in Irtysh River （China section） using molecular biology techniques. These results showed that this species was Diplostomum paracaudum, a new record of this kind of species in China. The similarity of partial 18S-ITS1-5.8S sequence between this sample and another D. paracaudum from GenBank was 99.6%. A phylogenetic tree analysis based on the partial 18S-ITS1-5.8S of 7 species in the genus of Diplostomum identified an out group species Gyrodactylus parvae, and supported our sample was closely related to D. paracaudum with a more than 50% bootstrap.