Complete mitochondrial genome of Arcuatula japonica (Mollusca: Mytilidae: Crenellinae) and its phylogenetic analysis

Arcuatula japonica (Dunker, 1857) (Mollusca: Mytilidae: Crenellinae) is a marine mussel distributed primarily in the northwestern Pacific. To clarify its evolutionary position and evaluate the taxonomic status of Crenellinae, we sequenced and characterized the complete mitochondrial genome of A. japonica. The mitogenome is 16,198 bp in length and contains 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and 1 non-coding control region (CR), with an A + T bias (68.7%). Phylogenetic analysis based on 13 mitochondrial PCGs supports a sister relationship between A. japonica and A. senhousia. The mitochondrial gene arrangement is conserved between these two species. In contrast, gene order, including that of PCGs, is highly variable among species representing different genera currently assigned to Crenellinae. Our findings provide important mitogenomic resources for future phylogenomic, taxonomic, and evolutionary studies of Crenellinae.