A review of the Cypriniform tribe Yunnanilini Prokofiev,2010 from China,with an emphasis on five genera based on morphologies and complete mitochondrial genomes of some species

The loach tribe Yunnanilini from China is reviewed here using morphological characters and complete mitochondrial genomes of select species.Molecular data suggest that the tribe Yunnanilini is not monophyletic and can be divided into three clades.Species of the Yunnanilus nigromaculatus group form an independent genus and are placed in Eonemachilus.In the phylogenetic tree,Y.jinxiensis clusters with Paranemachilus genilepis,and Y.pulcherrimus clusters with Micronemacheilus cruciatus,indicating that Y.jinxiensis and Y.pulcherrimus belong to Paranemachilus and Micronemacheilus,respectively.Based on while Y.jinxiensis and Y.pulcherrimus,are placed in Paranemachilus and Micronemacheilus,respectively.Yunnanilus niulanensis and Y.qujinensis are treated as junior synonyms of Eonemachilus caohaiensis.Eonemachilus,Micronemacheilus,and Yunnanilus are show short separation between anterior and posterior nostrils.The genera can be distinguished from each other by mouth structure,lateral line and cephalic lateral-line canals,and papillae on median part of both lips.The anterior and posterior nostrils of Heminoemacheilus and Paranemachilus are closely set.Paranemachilus and Micronemacheilus are distinguished by cheeks covered with scales and lips with papillae,respectively.Our phylogenetic tree and morphological characters support Traccatichthys as a valid genus,which can be distinguished from Micronemacheilus by anterior and posterior nostrils closely set(vs.clearly separated).Four species are placed in Traccatichthys.

基于DNA条形码基因和核基因的美丽小条鳅隐存多样性研究

为揭示华南地区美丽小条鳅(Micronemacheilus pulcher)的隐存多样性及其地理分布格局,同时为美丽小条鳅的精准管理和保护提供重要理论背景知识,本研究采集了华南地区多个水系19个地理群体共计102尾美丽小条鳅样本,测定了所有样本的DNA条形码标准基因(线粒体COI基因)与部分样本的糖基转移酶基因(Glyt基因),综合了系统发育分析、遗传距离估算、等位基因网状图分析、物种有效性界定等方法,基于COI基因的系统发育结果显示,美丽小条鳅存在两个主要谱系(I和Ⅱ),谱系Ⅰ主要由珠江水系、漠阳江水系、南流江水系群体构成,谱系Ⅱ由海南岛的陵水河水系和南渡江水系群体组成。另外,研究发现谱系Ⅰ可以细分为三个严格地理分布的子谱系(Ⅰ-1,Ⅰ-2和Ⅰ-3),其中子谱系Ⅰ-1由珠江水系的西江、北江和南流江水系的群体组成,子谱系Ⅰ-2和Ⅰ-3分别由珠江水系的东江群体和漠阳江水系群体组成;谱系Ⅱ可以分为子谱系Ⅱ-1和Ⅱ-2,分别由陵水河水系群体和南渡江水系群体组成。遗传距离估算发现谱系Ⅰ和Ⅱ之间的遗传距离达到5.83%,谱系Ⅱ的两个子谱系之间的遗传距离到达2.92%,大于2%的DNA条形码物种鉴定阈值。基于Glyt基因的系统发育分析未获得严格的谱系分化,但是等位基因网状图支持大陆群体和海南岛群体以及海南岛的陵水河水系群体和南渡江水系群体的进化独立性。基于COI基因的ABGD(automatic barcode gap discovery)和PTP(poisson tree process)分析和联合两个基因的BPP(bayesian phylogenetics and phylogeography)分析均支持谱系Ⅰ、子谱系Ⅱ-1和子谱系Ⅱ-2为三个独立物种,表明美丽小条鳅至少包含三个隐存种。研究结果表明美丽小条鳅的多样性可能被低估,亟需使用形态度量学、更高覆盖度的和多种类型的分子标记来全面系统揭示其隐藏的遗传多样性,为美丽小条鳅全面精准的管理保护提供数据支持。