Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Science, Liběchov, Czech Republic.
Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Academy of Science, Liběchov, Czech Republic; Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic.
Mol Phylogenet Evol. 2020 Oct;151:106894. doi: 10.1016/j.ympev.2020.106894. Epub 2020 Jun 18.
The Schistura robertsi species complex is a group of freshwater fish inhabiting streams in southeast Myanmar as well as in western and southern Thailand. In southern Thailand, the distribution exceeds the biogeographically important 'Surat Thani - Krabi line'. The complex is believed to include five described and one undescribed species, but monophyly and systematics of the group have never been studied explicitly. The present study aims to resolve the number of species within the Schistura robertsi group as well as their distribution areas and phylogenetic relations. We analysed mitochondrial and nuclear sequence data of 86 specimens from 47 localities and 18 morphological characters of 193 specimens. The phylogenetic analyses revealed the S. robertsi complex to be monophyletic and to be composed of ten major lineages. Six of them correspond to the known described or undescribed species, but another four newly identified clades reveal the existence of an overlooked diversity within the group. All genetic lineages are statistically highly supported and all are morphologically diagnosable, suggesting that they represent distinct species. The distribution areas of several clades overlap, the cases of direct co-occurrence show no sign of hybridisation.
罗氏沙鳅物种复合体是一群栖息在缅甸东南部以及泰国西部和南部溪流中的淡水鱼类。在泰国南部，其分布范围超过了具有重要生物地理意义的“素叻他尼-甲米线”。该复合体据信包括五种已描述和一种未描述的物种，但该群体的单系性和系统发育从未被明确研究过。本研究旨在确定罗氏沙鳅复合体中的物种数量及其分布区域和系统发育关系。我们分析了来自 47 个地点的 86 个样本的线粒体和核序列数据以及 193 个样本的 18 个形态特征。系统发育分析表明，罗氏沙鳅复合体是单系的，由十个主要谱系组成。其中六个与已知的已描述或未描述的物种相对应，但另外四个新鉴定的分支揭示了该群体中存在被忽视的多样性。所有遗传谱系在统计学上都得到了高度支持，并且所有谱系在形态上都可诊断，表明它们代表不同的物种。几个分支的分布区域重叠，直接共存的情况没有杂交的迹象。
