Liobagrus brevispina, a new species of torrent catfish (Siluriformes: Amblycipitidae) from the upper Chang‐Jiang basin, South China

A new species of Liobagrus is unearthed in the Nan‐Jiang flowing into the Jialing‐Jiang of the upper Chang‐Jiang basin in which currently recognized Chinese congeners have a concentrated distribution. This small‐sized (less than 100.0 mm LS) torrent fish belongs to the species group defined by the presence of a smooth posterior edge of the pectoral‐fin spine and upper and lower jaws of equal length or a lower jaw slightly longer than the upper jaw in length. It is distinct from Liobagrus aequilabris and Liobagrus formosanus by the presence of a pectoral‐fin spine extending short of (vs. beyond) the vertical through the dorsal‐fin origin, maxillary barbels reaching the middle of the pectoral fin (vs. pectoral‐fin insertion or slightly beyond), 17–19 anal‐fin rays (vs. 15–16 in L. formosanus), 39–41 (vs. 35–37 in L. aequilabris) post‐Weberian vertebrae and the pectoral‐fin spine length 3.6%–7.4% of LS (vs. 7.6–10.5 in L. aequilabris). It differs from Liobagrus marginatoides by the presence of upper and lower jaws of equal length (vs. a lower jaw slightly longer than the upper jaw in length) and a rounded or unevenly rounded (vs. subtruncate) caudal fin. The validity of the new species is confirmed by its monophyly recovered in a cytochrome b gene‐based phylogenetic analysis and its significant genetic distance with sampled congeneric species.