Phylogenetic inferences introduced on cytochrome b gene sequences data for six flatfish species (Teleostei, Pleuronectidae) and species synonymy between representatives of genera Pseudopleuronectes and Hippoglossoides from Far Eastern seas.

Cytochrome b (Cyt-b) gene was sequenced for six flatfish species and compared with seven other species belonging to Pleuronectiformes. Monophyly of the family Pleuronectidae representatives was fine supported by bootstrap or other means in several sequence-based trees on Cyt-b gene data. Results revealed that synonymy must be accepted for Hippoglossoides elassodon, and H. robustus, as well as for Pseudopleuronectes yokohamae, and P. schrenki.