Validation and re-description of Sinocyclocheilus aluensis Li et Xiao, 2005 (Cypriniforms: Cyprinidae)

Sinocyclocheilus aluensis was previously synonymized with S. angustiporus, but through the comparison of the specimens collected from Luxi County (type locality of S. aluensis) and type specimens of S. angustiporus, we identified several clear and stable characteristics to distinguish them. These findings suggest that S. aluensis should be considered as a valid species, as it can be distinguished from S. angustiporus by the position of the dorsal-fin insertion (posterior to vs. opposite to the pelvic-fin insertion), eye (22.4%-29.7% vs. 26.4%-38.9%, percentage of head length), eye-ball diameter (16.0%-23.6% vs. 21.3%-29.0%), and interorbital width (21.0%-32.3% vs. 19.7%-22.6%).