Analysis of diversity of CO I gene and system generation of nine species of chitons

Cytochrome c oxidase subunit I (CO I) genes from 9 chiton species in China’s coast area were sequenced. A phylogeny tree about these gene sequences were reconstructed together with other 4 CO I gene sequences of chitons from Genbank. The affinity genetic relationship and the taxonomic status of molecular evolution for these 13 chiton species were analyzed. The results show that Liolophura japonica and Onithochiton hirasei belong to Chitonidae, Acanthochiton rubrolineatus and Acanthochiton dissimilis belong to Acanthochitonidae, and Placiphorella japonica and Mopalia retifera belong to the same family Mopliidae. However, Lepidozona coreanica, Ischnochiton comptus, and Ischnochiton hakodadensis are not supposed to be referred to Ischnochitonidae according to the genetic distance analysis (L. coreanica, I. comptus, and I. hakodadensis are usually classed as Ischnochitonidae according to their morphological character). Furthermore, I. hakodadensis could not been classed as Ischnochiton, and it is more likely to be treated as a close relative of Lepidozona.