The complete mitochondrial genome of Caprella scaura (Crustacea, Amphipoda, Caprellidea), with emphasis on the unique gene order pattern and duplicated control region

The nucleotide and amino acid sequences and the gene order of the mitochondrial genome are highly informative for studying phylogeny, population genetics, and phylogeography. This study determined the complete mitochondrial genome of the caprellid species Caprella scaura. The mitochondrial genome of C. scaura has a total length of 15,079 bp, with an AT content of 66.43%. The mitochondrial genome contains typical gene components, including 13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes. In comparison with the mitochondrial genome of a gammarid, some distinct characteristics were found. For example, the order of the two conserved gene blocks is inverted between Gammaridea and C. scaura. In addition, two copies of almost identical control regions were found in the mitochondrial genome of C. scaura. These unique characteristics will be useful for determining the evolutionary history of the Caprellidea.