Pareuchiloglanis is a genus of sisorid catfishes native to Asia. These species are rheophilic catfish chiefly found in the headwaters of major rivers in South and East Asia. They originate from the Brahmaputra drainage in India, east and south to the Yangtze drainage in China and the Annamese Cordillera drainages in southern Vietnam. Two species are known from the Mekong River: P. myzostoma and P. gracilicaudata. Four species are known from the (upper Mekong River) drainage of China: P. abbreviatus, P. gracilicaudata, P. myzostoma and P. prolixdorsalis. Taxonomy The monophyly of this genus remains doubtful. In 2007, a study rejected the monophyly of this genus. The premaxillary tooth bands in the catfish tribe Glyptosternina are important in identifying genera; in Pareuchiloglanis, the tooth band is divided into two patches, appearing in two types. In one type, the premaxillary tooth patches appear separate, divided down the middle by a deeper indentation; this type is characteristic in P. feae. This group is distributed in and to the west of the Lancangjiang River and overlaps the distribution of Oreoglanis, Pseudexostoma and Exostoma. In the other type, the premaxillary tooth patches appear to be joined with a shallow indentation in the middle; this type is characteristic of all other species of Pareuchiloglanis. This group is distributed in and to the east of the Lancangjiang. Species There are currently 21 recognized species in this genus: Pareuchiloglanis abbreviata X. Li, W. Zhou, A. W. Thomson, Q. Zhang & Y. Yang, 2007 Pareuchiloglanis anteanalis S. M. Fang, T. Q. Xu & G. H. Cui, 1984 Pareuchiloglanis brevicaudatus V. H. Nguyễn, 2005 Pareuchiloglanis dorsoarcus (V. H. Nguyễn, 2005) Pareuchiloglanis feae (Vinciguerra, 1890) Pareuchiloglanis gracilicaudata (Y. F. Wu & Y. Chen, 1979) Pareuchiloglanis hupingshanensis Z. J. Kang, Y. X. Chen & D. K. He, 2016 Pareuchiloglanis longicauda (P. Q. Yue, 1981) Pareuchiloglanis macrotrema (Norman, 1925) Pareuchiloglanis myzostoma (Norman, 1923) Pareuchiloglanis namdeensis V. H. Nguyễn, 2005 Pareuchiloglanis nebulifera H. H. Ng & Kottelat, 2000 Pareuchiloglanis phongthoensis (V. H. Nguyễn, 2005) Pareuchiloglanis poilanei Pellegrin, 1936 Pareuchiloglanis prolixdorsalis X. Li, W. Zhou, A. W. Thomson, Q. Zhang & Y. Yang, 2007 Pareuchiloglanis rhabdura H. H. Ng, 2004 Pareuchiloglanis robusta R. H. Ding, T. Y. Fu & M. R. Ye, 1991 Pareuchiloglanis sichuanensis R. H. Ding, T. Y. Fu & M. R. Ye, 1991 Pareuchiloglanis sinensis (Hora & Silas, 1952) Pareuchiloglanis songdaensis H. D. Nguyễn & V. H. Nguyễn, 2001 Pareuchiloglanis tamduongensis V.