澜沧江大鳞高须鱼寄生指环虫属单殖吸虫一新种

Description of a New Species of Genus Dactylogyrus(Monogenea:Dactylogyridae)Parasitizing Hypsibarbus vernayi from the Lancang River,Yunnan Province

本文记述了位于云南西双版纳澜沧江水系勐腊(补远江)流域段(101°14′2″E,21°24′36″N,海拔570 m)大鳞高须鱼Hypsibarbus vernayi鳃上寄生的指环虫属Dactylogyrus一未定种。自然感染率为76.2%,感染强度为每片鳃3~10枚。未定种虫体平均大小为640µm×129µm,具2对眼点。后吸器由1对D.wunderi型中央大钩、1个长片状联结片和7对边缘小钩构成。交接器由交接管和支持器构成,交接管基部膨大呈球形,随后变细沿支持器直线延伸;支持器直管状,端部分两支为“并指状”,与交接管相联结,像拇指包绕住交接器。上述特征与我国鲃亚科Barbi-nae鱼类上已记录的指环虫(齿形指环虫D.denticulati、倒刺鲃指环虫D.spinibarbichthi、角鱼指环虫D.epalzeorhyn-chus、条纹指环虫D.lineatus)有明显差异。28S rDNA部分序列分析显示,本未定种与寄生于意大利路库玛雅罗鱼Squalius lucumonis上的尹文指环虫D.yinwenyingae亲缘关系最接近,但碱基相似度只有95%。结合形态和分子特征,本未定种为指环虫属科学上一新种,以采集地命名为补远江指环虫新种D.buyuanjiangensis sp.nov.。

This paper describes a new species of Dactylogyrus parasitized on the gills of Hypsibarbus vernayi.The host fish was collected from the Mengla(Buyuan River)basin section of the Lancang River system in Xishuangbanna,Yunnan Province(101°14′2″E,21°24′36″N,altitude:570 m).The new species is named after the place of collection,Dactylogyrus buyuanjiangensis sp.nov.A total of 21 Hypsibarbus vernayi were captured,and 16 of which were gill-infected with the fluke.The prevalence was 76.2%,and the infection intensity was 3-10 per gill.The average size of the new species is 640µm×129µm.The haptor contain 7 pairs of marginal hooks,and a pair of central hooks with one accessory piece.The central hook is D.wunderi type.There is only one accessory piece,which is long in shape.The copulatory complex consists of a copulatory tube and a hander.The base of the copulatory tube expands into a spherical shape and then narrows along the support line.The end of the hander is"parallel finger",straight tubular,connected to the intersecting pipe,like a thumb wrapped around the handover.There are significant differences between this species and recorded species(D.denticulati,D.spinibarbichthi,D.epalzeorhynchus,D.lineatus)in male copulatory complex and the haptor.Partial sequence analysis of the 28S rDNA showed that the unidentified species had the closest relationship with D.yinwenyingae,which is parasitic on Squalius lucumonis,Italy,while the base similarity was only 95%.Basing on the high host-specificity of the Dactylogyrus species and interspecific difference of the 28S rDNA fractional sequences between the new species and other reported species,we concluded that Dactylogyrus buyuanjiangensis sp.nov.is a scientifically undescribed new species.