Phylogenetic relationships of the Chinese cyprinid genusRhinogobioBleeker (Teleostei: Cyprinidae) based on sequences of the mitochondrial DNA control region, with comments on character adaptations.

Rhinogobiois a cyprinid genus restricted to the river drainages of China. Sequences of the mitochondrial DNA control region were determined for fourRhinogobiospecies and one outgroup species,Coreius heterodon, to investigate the phylogenetic relationships within the genus. The control region of theRhinogobiospecies ranges from 922 to 930 base pairs and comprises 930 base pairs inCoreius. Our phylogenetic analysis indicates two distinct lineages in the genusRhinogobio. The first includes onlyRR.ventralis. In the second lineage there are three species, two closely related speciesR.cylindricusandR.hunanensis, and their sister speciesR.typus. An analysis of character adaptations suggests an evolutionary trend in this genus towards a relatively lower body and caudal peduncle depth, a shorter dorsal fin, and a more anterior anus. In addition, there is a trend towards shorter barbels and relatively larger eyes. Some or all of these traits may be associated with a habitat shift from fast-flowing turbid rivers to slower-flowing clear river habitats. [ABSTRACT FROM AUTHOR]