基于四个线粒体基因片段的银鱼科鱼类系统发育

PHYLOGENETIC RELATIONSHIPS OF NOODLE-FISHES (OSMERIFORMES:SALANGIDAE) BASED ON FOUR MITOCHONDRIAL GENES

银鱼科鱼类是我国重要的经济鱼类,但其属间系统发育关系与属、种的界定尚存争议。研究使用线粒体12S/16S核糖体RNA、细胞色素c氧化酶亚基Ⅰ(COⅠ)基因部分序列以及NADH脱氢酶亚基1全长序列重建银鱼科属间的系统发育。结果显示银鱼科鱼类是单系群,白肌银鱼属在银鱼系统发育的基部,"大银鱼属+新银鱼属"、"间银鱼属+银鱼属"形成两个单系亚群,但日本银鱼属的位置没有很好解决。基于COI基因序列计算的"短吻-陈氏-太湖-近太湖新银鱼复合群"种间遗传距离为0—0.19%、"乔氏-寡齿新银鱼复合群"种间遗传距离为0%。整合研究结果与前人形态、分子证据,详细地讨论了银鱼的属、种分类。

Noodle-fishes（Osmeriformes： Salangidae） are important commercial fishery species in China and other Asian countries.Although these species are common in fresh water,estuarine and coastal habitats in East Asia,the phylogenetic relationships of noodle-fishes are still unresolved and the taxonomy at the genus or species level has been disputed.To elucidate the genus-level phylogenetic relationships of salangid fishes,partial sequences of mitochondrial 12S/16S ribosome RNA and cytochrome c oxidase subunit Ⅰ（COⅠ） genes and complete sequences of NADH dehy-drogenase subunit 1 gene were used in this present study.Phylogenetic relationships were constructed based on the combined data set of these 4 genes with 2464 bp after alignment,among which 788 sites were variable,and 723 sites were informative.Maximum Likelyhood and Bayesian methods were employed for phylogenetics analysis.Maximum Likelyhood and Bayesian analyses yielded same topology of trees.Results showed that the salangids was a mono-phyletic group.The genus Leucosoma occupied a basal position of the reconstructed Salangidae phylogeny.Two mo-nophyletic subgroups,‘Protosalanx ＋ Neosalanx’ and ‘Hemisalanx ＋ Salanx’ were also revealed.Within ‘Protosalanx ＋ Neosalanx’ subgroup,three primitive lineage were found：（1） Protosalanx chinensis and Neosalanx anderssoni;（2） ‘N.brevirostris-tangkahkeii-taihuensis-pseudotaihuensis complex’;（3） ‘N.jordani-oligodontis complex’.The inter-specific phylogenetic relationships within ‘N.brevirostris-tangkahkeii-taihuensis-pseudotaihuensis complex’ and ‘N.jordani-oligodontis complex’ couldn’t be clarified on the phylogeny tree.Moreover,inter-specific genetic distances were 0—0.19% for ‘N.brevirostris-tangkahkeii-taihuensis-pseudotaihuensis complex’ and 0% for ‘N.jordani-oligodontis com-plex’ based on partial sequences of mitochondrial COⅠgene.Within ‘Hemisalanx ＋ Salanx’ subgroup,Hemisalanx brachyrostralis and Salanx cuvieri were sister groups,and these two species together formed the sister group of S.ari-akensis.However,the systematic position of Salangichthys was still unresolved.Integrating findings in this study with morphological and molecular evidences from previously published studies,taxonomic status of noodle-fishes at the genus and species level were discussed detailedly.We concluded that Neosalanx anderssoni should be reclassified as Protosalanx anderssoni,belonging to the genus Protosalanx;Neosalanx tangkahkeii,N.taihuensis and N.pseuditai-huensis might be the synonyms of N.brevirostris;Neosalanx oligodontis and N.reganius are probably the synonyms of N.jordani;Hemisalanx prognathus would be the synonyms of H.brachyrostralis;Hemisalanx is invalid,so Hemisalanx brachyrostralis should be put in the genus Salanx;Leucosoma is a valid genus located at the basal position of Salangi-dae.Further researches on the phylogenetic position of Salangichthys are still needed.