The first mitochondrial genome of Balanus trigonus Darwin, 1854 (Sessilia: Balanidae) and molecular phylogeny within Cirripedia.

The triangle barnacle Balanus trigonus Darwin, 1854, a cosmopolitan inhabitant of tropical and warm temperate seas, is a member of robust system for the study of evolutionary processes in the intertidal zone. The first mitochondrial genome of B. trigonus is presented. The complete mitochondrial genome of B. trigonus is a circular molecule of 15,560 bp, which encodes 13 protein-coding genes (PCGs), 2 rRNA genes, and 22 tRNA genes. In comparison within Sessilia, the arrangement of the mitochondrial genome of B. trigonus is more similar to Megabalanus spp. than the congener Balanus balanus, which share a same inversion of a large gene block (P-nd4L-nd4-H-nd5-F). Phylogenetic analysis based on mitochondrial PCGs reveals that B. trigonus clusters with Acasta Sulcata (BP = 100), then grouped with Megabalanus volcano and Megabalanus ajax with high support (BP = 90). In further, more data and research are needed to reveal the phylogeny within Cirripedia.