A taxonomic review of the catfish identified as Glyptothorax zanaensis (Teleostei: Siluriformes: Sisoridae), with the descriptions of two new species

This study re-examined the taxonomic status of the sisorid catfishes usually identified as Glyptothorax zanaensis using a combination of morphometric and molecular data. Our results resurrect Glyptothorax longinema from the synonymy of G. zanaensis, and we describe two previously unnamed species as Glyptothorax granosus sp. nov. and Glyptothorax fucatus sp. nov. All four species are diagnosed and described in detail. Truss-based morphometrics combined with principal component analysis (PCA) detected three principal components (PCs) that can explain 86% of the total variation amongst species, which mainly reflect the characteristics of body depth, related depth, adhesive apparatus length, pectoral-fin length, caudal peduncle length, and barbel lengths. We also generated a phylogenetic hypothesis of these species using concatenated mitochondrial cytochrome b and d-loop gene sequences. Molecular dating analysis revealed a rapid speciation of Glyptothorax in the south-eastern corner of the Qinghai-Xizang Plateau from the middle Pliocene to early Pleistocene. A key to identify the Glyptothorax species from the Salween River drainage is also provided. (c) 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 165, 363389.