Mitogenome evidence for the existence of cryptic species in Coelomactra antiquata

Cryptic species which improve our understanding of species diversity and evolutionary histories within marine animals have been increasingly revealed in the marine realm. Coelomactra antiquate is an important commercial bivalve species, but has been suffering from severe population decline due to over-exploitation and deterioration of environmental conditions. To test the hypothesis that cryptic species might exist in C. antiquate presented in previous study, four complete mitogenomes of C. antiquate from northern and southern China were determined here. Comprehensive comparative analysis of the mitochondrial genomes of C. antiquate between northern and southern population reveals significant differences in genome composition, protein coding genes, tRNA genes, non-coding regions, genetic divergence and phylogenetic analysis. The results provide strong mitogenome evidence for the existence of cryptic species in C. antiquate. Besides, our results also support that comprehensive comparative analysis of mtDNA represents an accessible and powerful tool to identify cryptic species.