The complete mitochondrial genome of Eriocheir japonica sinensis (Decapoda: Varunidae) and its phylogenetic analysis

• The complete mitochondrial genome of Eriocheir japonica sinensis was determined.
• This mitochondrial genome has the typical gene organization and order of Eriocheir mitogenomes.
• E. j. sinensis has a close evolutionary relationship with the crabs in Varunidae.

The complete mitochondrial genome (mitogenome) can provide novel insights into understanding the mechanisms underlying mitogenome evolution. In this study, the complete mitogenome of Eriocheir japonica sinensis (Decapoda: Varunidae) was determined to be 16,378 bp, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a D-loop region. The AT skew of the E. j. sinensis mitogenome was slightly negative (−0.016), indicating a higher number of T compared with A nucleotides. The nucleotide composition of the mitogenome was also biased toward A + T nucleotides (71.6%). All PCGs were initiated by ATN codons. Eight of the 13 PCGs harbored the incomplete termination codon by T, or TA. All other tRNA genes displayed a typical clover-leaf structure of mitochondrial tRNA. The D-loop region of the E. j. sinensis mitogenome was 918 bp in length. Based on 13 PCGs, phylogenetic analysis confirmed the placement of E. j. sinensis within the Varunidae.