【作者】 宋英；

【导师】 聂品； 王桂堂；

【作者基本信息】 中国科学院研究生院（水生生物研究所） ， 水生生物学， 2006， 博士

【摘要】 鳋科与锚头鳋科是危害我国淡水养殖鱼类的两大主要寄生桡足类,本论文利用分子生物学的方法对鳋科和锚头鳋科的寄生鳋类进行了系统发育分析,并通过分析鳋科中华鳋属三种中华鳋与其宿主的协同进化关系,探讨中华鳋物种的形成机制。以18S、28S和18S-28S rDNA的联合片段为遗传标记研究鳋科4属共14种和锚头鳋科2属3种鳋之间的系统发育关系,支持鳋科和锚头鳋科为单系。在鳋科内部,中华鳋属与三指鳋属为单系,鳋属为复系,除了掘凿鳋和雅鲁藏布鳋的进化位置不十分明确外,所有的结果都支持将整个鳋科分为三个大类群,中华鳋属-鳋属类群为中华鳋属和鳋属的固着鳋,假鳋属-鳋属类群为假鳋属和部分鳋属的种类,三指鳋属-鳋属类群为三指鳋属和鳋属的奇异鳋。不同的是以18S rDNA为标记用最大似然法、邻接法和贝叶斯法建树的结果都支持中华鳋属-鳋属类群与假鳋属-鳋属类群的亲缘关系更近些,以28S rDNA为遗传标记支持假鳋属-鳋属类群与三指鳋属-鳋属类群的亲缘关系更近些,根据寄生桡足类的演化规律从半寄生到完全寄生状态,18S rDNA的建树结果更支持这一结论。Kishino-Hasegawa检验的结果支持将掘凿鳋和奇异鳋归为假鳋属-鳋属类群的假设,不支持将固着鳋归为假鳋属-鳋属类群的假设。在锚头鳋科内部,以28S rDNA为标记用最大似然法、邻接法和贝叶斯法建树的结果都支持狭腹鳋属为单系。以部分18S rDNA序列为遗传标记进行寄生桡足类和自由生活桡足类的系统发育研究,支持杯口水蚤目、剑水蚤目、管口水虱目、猛水蚤目和哲水蚤目为单系。经典支序分类支持管口水虱目与怪水蚤亚目先形成姊妹群,然后与杯口水蚤目聚在一起,而剑水蚤目与上述三目的亲缘关系较远些,本实验用三种建树方法所建成的树都支持杯口水蚤目和剑水蚤目的亲缘关系更近,然后与管口水虱目的种类聚在一起,说明管口水虱目、杯口水蚤目和剑水蚤目有共同的祖先。另外,分子进化分析的结果也支持锚头鳋科应归为剑水蚤目,鱼虱科应归为管口水虱目。为了探讨中华鳋的分子系统进化关系和物种形成机制,将采自鲢、鳙上的鲢更多还原

【Abstract】 Copepods in the Ergasilidae (Copepoda: Poecilostomatoida) and Lernaeidae (Copepoda: Cyclopoida) are two major groups of parasitic copepods on freshwater fish. The present study aimed to illustrate the phylogenetic relationship among species in the families Ergasilidae and Lernaeidae, and to understand the phylogenetic relationship among three species in the Sinergasilus (Ergasilidae) with the analysis of the Sinergasilus-host co-evolutionary relationship.A total of 14 species belonging to 4 genera in the Ergasilidae and 3 species to 2 genera in the Lernaeidae were obtained from 24 species of fish in China, and the 18S, 28S rDNA sequences were cloned from the collected parasitic copepods. Phylogenetic analyses using partial 18S and partial 28S rDNA sequences and combined 18S-28S rDNA sequences suggested that both Ergasilidae and Lernaeidae are monophyletic. In the Ergasilidae, the genera Sinergasilus and Paraergasilus are monophyletic, and Ergasilus is paraphyletic. Except the uncertain position of E. scalaris and E. yaluzangbus, copepods in the Ergasilidae can be further separated into three main clades, i.e. the Sinergasilus-Eragsilus clade including species in the Sinergasilus and E. anchoratus in the Ergasilus, the Pseudergasilus-Ergasilus clade including P. parasiluri in the Pseudergasilus and some in the Ergasilus, and the Paraergasilus-Ergasilus clade including species of Paraergasilus and E. peregrinus in the Ergasilus. All the three trees generated by using maximum parsimony, neighbor-joinning and Bayesian inference methods support thePseudergasilus-Ergasilus clade has a closer phylogenetic relationship with the Sinergasilus-Eragsilus clade based on 18S rDNA,and a closer relationship with the Paraergasilus-Ergasilus clade based on 28S rDNA sequences. The evolutionary rule更多还原