Molecular systematics of the Asian torrent minnows (Ostariophysi: Psilorhynchidae) inferred from nuclear and mitochondrial DNA sequence data

The phylogenetic relationships between members of the South Asian family Psilorhynchidae are investigated using both mitochondrial and nuclear DNA sequence data. Phylogenetic hypotheses were derived from maximum likelihood and maximum parsimony analyses of a three gene concatenated data set, including cytochrome c oxidase subunit 1 (640bp), cytochrome b (1140bp) and exon 3 of the recombination-activating gene 1 (1500bp). Our investigation provides strong support for the monophyly of two species groups of Psilorhynchus (the P.balitora and P.nudithoracicus species groups) and corroborates previous hypotheses on the phylogenetic position of the Western Ghats species Psilorhynchus tenura based on morphology. Basal relationships within Psilorhynchus were poorly supported and are worthy of further investigation. A fossil calibrated relaxed molecular clock estimates the split between Psilorhynchus and its sister group to have occurred within the Eocene/Oligocene, with subsequent diversification in the Miocene.