中国近海鯻科鱼类系统发育初探

On phylogenetic relationships of Teraponidae in coastal waters of China

分析了中国鯻科鱼类4属6种17尾鱼的线粒体16S rRNA基因3′端部分序列特征。结果表明,在鯻科鱼类507 bp的碱基序列中有变异位点57个,简约信息位点55个,A+T含量(50.3%)高于G+C含量(49.8%),转换/颠换比为2.7。在邻接树和最大似然树上,鯻科鱼类聚类为2个分支,其中鯻属细鳞鯻独立为一支,其余属种组成另一分支,不支持Vari(1978)关于鯻科15个属中匀鯻属为最早分化类群的结论;鯻属的细鳞鯻和鯻鱼并未聚类在一起,表明二者亲缘关系较远,或为不同属,与Lee等报道相一致。由于鯻科鱼类属种较多,本文所分析的样品有限,且鯻科系统分类长期存在争议,因而需要采用多个线粒体和核基因联合分析更多属种,才能确定可否另立新属,并进一步明确鯻科鱼类的系统发育关系。

The partial sequence characters in 3′ terminal region of 16S ribosomal RNA genes from 17 individuals belonging to 6 species in 4 genera,including Leiopotherapon,Rhynchopelates,Pelates and Teropon within the family Teraponidae,were analyzed.Of the aligned 507 bp nucleotide sequences,there were 57 variable sites and 55 information sites.The content of A＋T and G＋C of the gene were 50.3% and 49.8%,respectively.The ratio of transition verse transversional was 2.7.In the phylogenetic trees constructed by neighbor-joining（NJ） and Maximum Likelihood（ML） methods,the analyzed teraponid perches were divided into two clades,the divergence of the clade Terapon jarbua from the other clade including the remained genera and species was inconsistent with Vari＇s taxonomic revision,which suggested the most primitive status of Leiopotherapon in the Teraponidae.Terapon theraps and Terapon jarbua didn＇t cluster together in both phylogenetic trees,and the distant phylogenetic relationships in the same genus suggested they might belong to different genera which was congruent with Lee Tsai＇s report.However,due to the majority species and genera in the family Teraponidae were not analyzed in the present study,and the phylogenetic relationships within the family have long been controversial,sequences of multiple mitochondrial and nuclear gene from more genera and species in the family should be analyzed to determine whether Terapon theraps should be elevated to new genus and further clarify the phylogenetic relationships within the family.