The Phylogeny and Morphological Adaptations ofCyclotus taivanusssp. (Gastropoda: Cyclophoridae)

By traditional classification, there are five Cyclotus taivanus subspecies in the low mountainous area of Taiwan and Okinawa: C. taivanus adamsi, C. t. dilatus, C. t. diminutus, C. t. peraffinis, and C. t. taivanus. The molecular phylogenetic relationships of this group have never been discussed. In order to investigate the relationships between C. taivanus ssp., we sequenced part of the mitochondrial COI and the 16S rRNA gene from 26 sampling sites. We also measured 9 shell traits for morphological analysis. Even though morphological PCA analysis revealed a more or less continuous distribution of individuals in morph-space, the two highly divergent haplotype clades in molecular analysis indicated the presence of two independently evolving lineages. Our results indicated that the sequence divergence between the two independent clades was almost as high as that among other Cyclophoridae species found previously. Therefore, from the viewpoint of taxonomy, C. t. adamsi should be considered a valid s...