To approach the taxonomy of large and complex animal groups it is of advantage to focus on species groups with shared derived character state. We investigate the composition, morphological characteristics and relationships of and within the Schistura cincticauda species group, whose members are small freshwater fishes that inhabit streams and rivers in eastern Myanmar and western and southern Thailand. A phylogenetic analysis using molecular genetic markers demonstrated the monophyly of this group; a combined genetic and morphological analysis revealed the inclusion of at least twelve species. They share the presence of a pair of black marks on the lower lip, one on each side of the median interruption (these marks may be reduced to few melanophores or even missing in some individuals). Additionally, all species share a small body size (max. 60 mm SL), an incomplete lateral line reaching at most to vertical through anal-fin base, and the absence of sexual dimorphism. Each of the 12 species is diagnosed by a unique combination of character states in fin ray numbers, anus position, presence/absence of an axillary pelvic lobe, and colour pattern. The distribution areas of several species overlap and five cases of syntopic occurrence are known. Five unnamed species are described herein.

为了对大型和复杂的动物群体进行分类，重点关注具有共同衍生特征状态的物种群体是有利的。我们研究了Schistura cincticauda物种组的组成、形态特征和关系，该物种组的成员是栖息在缅甸东部以及泰国西部和南部的溪流和河流中的小型淡水鱼。使用分子遗传标记的系统发育分析证明了该群体的单系性；综合遗传和形态学分析显示，其中至少包含十二个物种。他们的下唇上都有一对黑色标记，中线中断的每一侧都有一个（这些标记可能会减少到很少的黑色素细胞，甚至在某些个体中消失）。此外，所有物种的体型都很小（最大 60 毫米 SL），侧线不完整，最多通过臀鳍基部垂直延伸，并且不存在性别二态性。这 12 个物种中的每一个都是通过鳍条数量、肛门位置、腋窝骨盆叶是否存在以及颜色图案等特征状态的独特组合来诊断的。已知多个物种的分布区域有重叠，并有五例同位出现的情况。本文描述了五个未命名的物种。