为了获知长江刀鲚寄生的异钩铗虫的分类学地位,采用光学、扫描电子显微镜和分子遗传扩增28S rRNA基因5'端部分序列相结合的方法,对长江刀鲚寄生的异钩铗虫进行种属鉴定和形态学研究。结果显示,后吸器与体前区分不明显,含有四对不对称的吸铗,其中一侧的前2个开放几丁质吸铗明显大于其余6个封闭的吸铗,虫体尾部带有二对端钩,卵两端具有较长的极丝。序列分析显示,林氏异钩铗虫与六棘异钩铗虫相似度为100%,邻接法构建分子进化树中处在同一分支。经形态及分子综合分析鉴定,此寄生虫为林氏异钩铗虫。
A parasite was isolated from Coilia nasus collected from Yangtze River. Morphological(light, scanning electron microscopes)and molecular(28S rRNA amplification)methods were used to identify the species of the isolates. Their typical characteristics: haptor not clearly distinguished from body proper, provided with 4 pairs of heteromorphic clamps. Two clamps on one side are larger than other six clamps. Narrow posterior appendage with 2 pairs of sharp hooks and egg with long filament. The results of sequence alignment showed 100% homology to 28s of Heteromazocraes hexacantha. Neighbor-joining methods of phylogenetic tree also showed that the isolates were in the same clade with H. hexacantha, These results suggested that this parasite is Heteromazocraes lingmueni, and its 28S rRNA was measured for the first time in this study.