DNA barcoding of hermit crabs of genus Clibanarius Dana, 1852 (Anomura: Diogenidae) in the Ryukyu Islands, southwestern Japan

The diogenid hermit crab genus Clibanarius Dana, 1852 is a group of decapod crustaceans commonly found in tropical or subtropical shallow waters. The species of the genus are usually characterized by distinct color patterns in life, but the identification of colorless specimens preserved in ethanol is sometimes very difficult. DNA barcoding can facilitate species identification and recognition. In this study, we determined partial sequences of the cytochrome oxidase I (COI) gene of 11 Clibanarius species commonly found in the intertidal zones of the Ryukyu Archipelago, southwestern Japan. The sequences can be used as nametags to distinguish each of the 11 species, as the data differ for each species. The COI gene sequences of Clibanarius show an AT bias, especially in the third codon position (A+T = 76.2%), as has been reported for some other anomuran species. Phylogenetic analyses based on the sequences also offer some suggestions on the interspecific relationships of Clibanarius.