Monophyly and phylogenetic relationships of the catfish genus Glyptothorax (Teleostei: Sisoridae) inferred from nuclear and mitochondrial gene sequences

Glyptothorax Blyth (1860) is the most species-diverse and widely-distributed genus in the Sisoridae, but few studies have examined monophyly of the genus and phylogenetic relations within it. We used the nuclear RAG2 gene and mitochondrial COI and Cyt b genes from 50 of the approximately 70 species to examine monophyly of Glyptothorax and phylogenetic relationships within the genus. Molecular phylogenetic trees were constructed using maximum parsimony, maximum likelihood and Bayesian inference methods. All methods strongly supported monophyly of Glyptothorax, with Bagarius as its sister group. Both analyses of two- and three-gene datasets recovered nine major subclades of Glyptothorax, but some internal nodes remained poorly resolved. The phylogenetic relationships within the genus and existing taxonomic problems are discussed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Over two-thirds of current known Glyptothorax fishes were sampled. ► First molecular evidence supported this genus as monophyletic. ► Nine subclades were revealed both from two-gene and three-gene datasets. ► Thoracic adhesive apparatus is useful in diagnosing species but not in elucidating phylogenetic relationships. ► Current taxonomy of some species requires reexamination.