The complete mitochondrial genome of an endangered triton snail (Littorinimorpha: Charoniidae) from South Korea.

The complete mitochondrial genome of an endangered triton snail (Littorinimorpha: Charoniidae) from South Korea was determined with the size of 15,330 bp, which contained 13 protein-coding genes, 22 tRNAs, and two rRNAs. The overall features of the mitochondrial genome are similar to those of typical gastropod mitochondrial genomes, except for the absence of a control region (CR): a conserved gene order, a high A + T content (67.45% for ), preference for AT-rich codons, etc. It is the second mitochondrial genome reported from this species after Cho et al. (2017), and there is ca. 98% sequence similarity between those of the species. According to the maximum-likelihood tree, placed within the monophyletic Tonnoidea, forming a monoclade with Cypraeoidea and Stromboidea within Littorinimorpha. Interestingly, we confirmed that Vermetoidea is placed at the basal position of the monophyletic Littorinimorpha.