舌鳎亚科Cynoglossinae鱼类基于COI条形码的系统发育关系

摘要

Based on cytochrome oxidase subunit I (COI) barcoding marker of 33 flatfishes in the subfamily Cynoglossinae of Pleuronectiformes, the molecular phylogenetic trees were constructed by maximum likelihood and Bayesian inference method for the Cynoglossus phylogenetic analysis. The results showed that fishes of Cynoglossinae are one monophyletic group, which has a stable sister-group relationship with Symphurinae. In the taxa of this study, fishes of Paraplagusia clustered into a shallow branch, forming a late specialization group of Tongue soles. The genus Cynoglossus was divided into eight main branches. Species composition of these eight branches differs from that in the classification system based mainly on morphological characters, including numbers of lateral lines and nostrils. The species in four branches were similar to four groups (canariensis, heterolepis, arel, and cynoglossus) out of the six from Menon’s system based on the morphological characteristics, while the kopsii group showed a great difference in branches classification. In addition, the K2P genetic distances among the eight branches of Cynoglossus were bigger than those in Paraplagusia subgenus, which indicates a further split among species or subgenus. The data of K2P genetic distance analysis also revealed that the Cynoglossus lighti Norman is a junior synonym of Cynoglossus joneri Günther, and that Cynoglossus purpureomaculatus Regan is a junior synonym of Cynoglossus abbreviatus (Gray).%以线粒体细胞色素氧化酶辅酶I (COI)条形码为分子标记，利用最大似然法和贝叶斯推断构建了分子系统发育树，对鲽形目 Pleuronectiformes舌鳎亚科 Cynoglossinae鱼类进行系统发育分析，结果表明所研究的28种舌鳎亚科鱼类形成了单系群，然后和无线鳎亚科 Symphurinae 鱼类形成稳定的姐妹群关系。所有须鳎属 Paraplagusia种类聚成一支，形成了舌鳎鱼类晚期一个比较特化的类群；舌鳎属 Cynoglossus 鱼类并没有形成一个单独的分支，分成了8个主要类群。舌鳎属的这种分支结果与按照侧线及鼻孔数目特征进行分类的结果差异较大，但是和Menon所划分的部分种组(group)的结果相近，即canariensis、heterolepis、arel、cynoglossus 4个种组的种类划分和本研究的结果基本一致，但kopsii 种组的种类组成则存有较大的差异。同时， K2P遗传距离分析的结果表明，舌鳎属内的种类已分化形成了不同的类群，有些类群之间已超出了亚属级分化，因此分类关系可能被低估了。同时遗传距离分析的结果支持长吻红舌鳎Cynoglossus lighti为短吻红舌鳎C. joyneri、紫斑舌鳎C. purpureomaculatus为短吻三线舌鳎C. abbreviatus的同物异名。