中文摘要：

本文记述了云南澜沧江水系景洪流域段（100°47＇43″E,22°0＇28″N）鳘条Hemiculter leucisculus（Basilewsky,1855）鳃丝上寄生指环虫属Dactylogyrus 2新种,以采集地命名为版纳指环虫Dactylogyrus bannaensis sp.nov.和景洪指环虫D.jinghongensis sp.nov.。版纳指环虫和景洪指环虫均为双联结片虫,基于后吸器,尤其是中央大钩、边缘小钩和交接器的形态学特征,鉴定为指环虫属科学上2新种。版纳指环虫交接器的形态有别于记录种船茎指环虫D.nilkolskyi Gussev,1955,版纳指环虫的交接管呈长带状,延伸至虫体左侧边缘阴道口处,末端微弯;感染率100%（40/40）。寄生于同一宿主的景洪指环虫,其交接器的形态有别于记录种红鲌指环虫D.erythroculteris和锥花指环虫D.pannosus,景洪指环虫的交接器呈彩虹状,交接管的一端基部膨大成漏斗状,另一端折叠;支持器＂V＂形,且中间包绕交接管;感染率100%（40/40）。

英文摘要：

This study described two new species of the genus Dactylogyrus,which were collected from the gills of the cyprinid fish Hemiculter leucisculus（ Basilewsky,1855）. The cyprinid fish were collected from the Lancang River,Jinghong basin of Yunnan province,100°47＇43″E,22°0＇28″N. The two new Dactylogyrus species are freshwater species and doublebar species. Based on the morphological differences of the types of haptoral sclerites and male copulatory organs（ MCOs）,the new two species Dactylogyrus bannaensis sp. nov. and D. jinghongensis sp. nov. were named according to the location of their hosts,respectively. D. bannaensis sp. nov. was distinguished by the different features from all the recorded species of the genus,especially D. nilkolskyi Gussev,1955. D. bannaensis sp. nov. has a male copulatory organ with a copulatory tube that elongate into left body margin of the parasite,distally recurved,directed straight process,long-ribbon-like,also possessing a complex accessory piece. And the infection rate of this parasite is 100%（ 40 /40）. The other new species D. jinghongensis sp. nov.,parasitizes the same host as Dactylogyrus bannaensis sp. nov.,is distinguished by the rainbow-like copulatory organ from its congeners（ D. erythroculteris and D. pannosus）. For the MCOs of D. jinghongensis,one of the ends expansion and funnel-type,distally extending to shaft fold and a V-type accessory piece,middle part enclosing copulatory tube and distal part process an attenuated tube. The infection rate of D. jinghongensis is also 100%（ 40 /40）.