First mitochondrial genome for the red crab (Charybdis feriata) with implication of phylogenomics and population genetics

In this study, we first described the complete mitochondrial genome for the red crab (Charybdis feriata), elucidated its phylogenetic relationship among 20 species within Decapoda, and estimated the population genetic diversity. The mitochondrial genome was 15,660 bp in size and encoded 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and two ribosomal RNA genes. The gene arrangement of the mitochondrial genome was the same as that of its sister species, C. japonica. Phylogenomic analysis suggested that genus Charybdis should be classified into subfamily Portuninae but not into subfamily Thalamitinae. Moreover, a total of 33 haplotypes of complete cytochrome c oxidase subunit I gene were defined in 70 individuals of C. feriata derived from three localities. Haplotype diversity and nucleotide diversity values among three localities indicated a high level of genetic diversity in C. feriata. AMOVA analysis suggested a low level of genetic differentiation among the three localities (F(ST) = 0.0023, P > 0.05). Neutrality tests and mismatch analysis revealed that C. feriata might have undergone a population expansion event that possibly occurred in the last 61,498 to 43,814 years. This study should be helpful to better understand the evolutionary status, and population genetic diversity of C. feriata and related species.