The RAPD results illustrate that the phylogenetic relationship betweenBothriocephalid tapeworm parasitic in Grass carpCtenopharyngodon idellus(C. et V. and Common carp(Cyprinus carpio L.)from different regions ofChina is infraspecific with noticeable variance bwtween them. Thephylogenetic trees based on the 3 sequences analyses above are constructed, which show the following relationships:Bothriocephalid tapeworms fromGrass carp, Common carp and Luciobrama are found to be monophyletic, and are very close to Bothriocephalus opsariichthydis, but are divergent toanother monophyletic group comprising Bothriocephalid tapeworms fromZacco, Hemiculter and Leuciscus. On the basis of phylogenetic reconstruction, autapomorphic species conceptis used in species delimitation suitablefor determining four species in the present study:B. acheilognathi, B. opsariichthydis, and two other bothriocephalids parasitic respectively inHemiculter and Leuciscus. It is also deduced that the differentiation time ofBothriocephalid tapeworms parasitic in cyprinids is earlier than that of theirhosts, and the most recent specification happened about one million yearsago. Key words Bothriocephalid tapeworm Molecular Systematics
具体成果有：通过RAPD分析探明了我国不同地理分布的草、鲤鱼头槽绦虫的亲缘关系属于种下水平，并存在较高变异；通过基因合并分析重建头槽绦虫的系统发育关系，表明草鱼、鲤鱼及鯮鱼头槽绦虫是单系群，它们与马口鱼头槽绦虫亲缘关系较近，而与〓条、宽鳍鱲及雅罗鱼头槽绦虫构成的另一单系群亲缘关系较远；在此基础上，提出符合头槽绦虫种的界定的独征物种概念，据此确定鲤科鱼类寄生头槽绦虫的四个种：鱊头槽绦虫，马口鱼头槽绦虫，以及另两种分别寄生于〓条和雅罗鱼的头槽绦虫：根据上述研究推断鲤科鱼类寄生头槽绦虫的分化年代早于其宿主，最近的一次物种形成距今约一百万年左右。