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 <i>Yunnanilus nigromaculatus</i> group form an independent genus and are placed in <i>Eonemachilus</i>. In the phylogenetic tree, <i>Y. jinxiensis</i> clusters with <i>Paranemachilus genilepis</i>, and <i>Y. pulcherrimus</i> clusters with <i>Micronemacheilus cruciatus</i>, indicating that <i>Y. jinxiensis</i> and <i>Y. pulcherrimus</i> belong to <i>Paranemachilus</i> and <i>Micronemacheilus</i>, respectively. Based on morphological data, <i>Y. bailianensis</i> and <i>Y. longibarbatus</i> are placed in <i>Heminoemacheilus</i>, while <i>Y. jinxiensis</i> and <i>Y. pulcherrimus</i>, are placed in <i>Paranemachilus</i> and <i>Micronemacheilus</i>, respectively. <i>Yunnanilus niulanensis</i> and <i>Y. qujinensis</i> are treated as junior synonyms of <i>Eonemachilus caohaiensis</i>. <i>Eonemachilus</i>, <i>Micronemacheilus</i>, and <i>Yunnanilus</i> 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 <i>Heminoemacheilus</i> and <i>Paranemachilus</i> are closely set. <i>Paranemachilus</i> and <i>Micronemacheilus</i> are distinguished by cheeks covered with scales and lips with papillae, respectively. Our phylogenetic tree and morphological characters support <i>Traccatichthys</i> as a valid genus, which can be distinguished from <i>Micronemacheilus</i> by anterior and posterior nostrils closely set (vs. clearly separated). Four species are placed in <i>Traccatichthys</i>.