Molecular phylogenetic interrelationships of the south Asian cyprinid genera Danio, Devario and Microrasbora (Teleostei, Cyprinidae, Danioninae)

Molecular analysis of mitochondrial cytochrome b sequences from 159 species of the family Cyprinidae supports the subfamily Danioninae, of which Rasborinae is shown to be a junior synonym. Analysis of combined cytochrome b and a fragment of the nuclear rhodopsin gene from 68 species, including 43 species representing the subfamily Danioninae, supports phylogenetic distinctness of Danio and Devario. In the combined molecular analysis Microrasbora rubescens, Chela, Laubuca, Devario, and Inlecypris form a clade with M. gatesi, M. nana and M. kubotai being in sister group position to the rest. The sister group of this Devario clade is Danio. Inlecypris is synonymized with Devario. Microdevario, new genus, is proposed for M. gatesi, M. nana and M. kubotai, supported by morphological characters. In the cytochrome b analysis, M. rubescens falls outside Devario, and there is no morphological support for including M. rubescens in Devario. In the cytochrome b analysis Esomus + Danionella is the sister group of Danio and Devario clades, whereas in individual rhodopsin and combined analyses Esomus is the sister group of Danio, and of Danio and the Devario clade, respectively. Sundadanio presents at least one strong morphological synapomorphy with Danio, but is positioned in molecular trees either as a member of the Cyprininae or as sister group of the remaining Danioninae. In the morphological analysis, small-sized species grouped together based on shared reductions that are not necessarily synapomorphies. In the molecular analysis, small-sized species such as Danionella and Sundadanio possess long branches and their position varies, but they did not group together. This suggests morphological homoplasy, but phylogenetic positions are not well supported in the molecular analyses