中文摘要：

记述了澜沧江云南省西双版纳景洪流域段（22°00.288＇N,100°47.430＇E）奇额墨头鱼Garra mirofrontis寄生指环虫属Dactylogyrus单殖吸虫一新种：澜沧江指环虫Dactylogyrus lancangjiangensis sp.nov.。宿主鱼类的自然感染率为68%（19/28）。吸虫平均大小为317μm×101μm。后吸器由1对中央大钩、7对边缘小钩、联结片和副联结片组成;联结片呈一字形,中部狭窄,两端较宽;副联结片呈月牙形;交接器包括交接管和支持器,交接管基部膨大呈球形,后部缢缩形成细管,并盘曲成3~5圈螺旋;支持器呈复杂棒状,交接管端部从中穿过。本种在后吸器和雄性交接器上与指环虫属已记录种存在明显差异,同时鉴于单殖吸虫具有较强的宿主特异性,认为该种是科学上一未记录种。模式标本保存于云南师范大学生命科学学院。

英文摘要：

A new species of genus Dactylogyrus （Monogenea： Dactylogyridae） , Dactylogyrus lancangfiangensis sp. nov. , from gills of the host Garra mirofrontis （Cyprinidae） was described in this study. The host was collected from Jinghong city of Lancang River basin, Xishuangbanna of Yunnan Province, 22 °00. 288′ N, 100 °47. 430′ E. Out of the 28 fishes, 19 were infected with the new parasites with prevalence 68%. The mean total body length was about 317 μm, and the mean to- tal body width was 101 μm. The haptor of the new species was consisted of a pair of anchors, 7 pairs of marginal hooks and a connection piece and a accessory connection piece. The connection piece was line-shaped, and became narrow in the mid- dle but wide on both ends; the connection accessory piece was moon-shaped. The copulatory organs were prominent with copulatory tube and hander. The base of copulatory tube was spherically dilated and directly narrowed to form a very thin tube bending 3 to 5 spirals. The hander was clavate and complex, and the end of copulatory tube was throughout the han- der. The taxonomic feture of the new species was distinctly distinguished from the recorded Dactylogyrus species, especially the male copulatory organs and haptoral sclerites. In view of the host-specificity and coevolution between Monogenea-fish as- sociations, D. lancangjiangensis sp. nov. was considered as a new species. The specimens were conserved in School of Life Sciences, Yunnan Normal University.