Abstract
Melibe japonica is the rarely identified nudibranch species in Korean and Japanese waters. Total mitochondrial genome of M. japonica collected from the coastal water of Busan, Korea, was determined by the bioinformatic assembly of the contigs generated by Illumina Miseq platform. The circular complete mitochondrial genome of M. japonica was 13, 216 bp in length, which contains 13 proteins, 2 ribosomal RNAs, and 22 tRNAs. Mitochondrial gene order of M. japonica is considerably different from the mitochondrial genome of Melibe leonina in which 6 genes (ND1, COX2, CYTB, ND4L, ND5, and ND6) were differently located. Phylogenetic analysis with COI regions showed that M. japonica is most closely related to Melibe viridis. However, not all Melibe species formed a single clade based on the phylogenetic analysis by COI region and more mitochondrial genomes in this genus should be further studied to have a better knowledge of the evolutional relationship of the nudibranchs.