Phylogenetic analysis of selected cyprinids inferred from sequencing of a mitochondrial cytochrome c oxidase I (COl) gene

This study examines the phylogenetic relationships of 21 selected freshwater cyprinids using sequence analysis of mitochondrial DNA cytochrome c oxidase I (COl) gene (464 base pairs). The phylogenetic study supported the monophyletic status between genus Tor and Neolissochillus, although their positioning within the mahseer clade (together with mahseers from South Asia) remained unresolved. Thus, the current result supported their taxonomic distinction and further erected the reclassification of Neolissochillus stracheyi from the genus Tor (previously classified as Tor soro into the genus Neolissochilus based on morphological characters such as the absence of the median lobe. The phylogenetic results also showed that the genus Barbus (represented by Barbus barbus) was the closest taxa to the genus Tor, followed by Cyprinus carpio and Barbonymus gonionotus. Another interesting finding was that B. gonionotus was phylogenetically distinct from its morphologically similar species, Barbonymus schwanenfeldii (K2P distance value = 15.1%) and did not group together in a single Barbonymus clade. The high genetic divergence observed between B. schwanenfeldii and B. gonionotus recommends the taxonomic revision of the latter barb from its current position within the genus Barbonymus. However, shortcomings of our results are clearly recognized and data should be treated with great caution, since it was based on a limited number of samples and a single maternally inherited gene (COl). Overall, the study managed to provide an insight into the phylogenetic relationships among cyprinids under study.