The complete mitochondrial genome of the freshwater crab Sinolapotamon patellifer (Decapoda: Brachyura: Potamoidea).

We report the complete mitochondrial genome of Sinolapotamon patellifer for the first time, which is found to be 16,547 base pairs in length, and contains 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA), and one non-coding AT-rich region known as the D-loop. In addition, the mitogenome has 17 intergenic regions ranging from 1 to 1512 bp in length. The mitochondrial genome of S. patellifer is the first mitochondrial genome under the genus Sinolapamon, providing DNA data for species identification, enriching the species diversity of Brachyura, and providing a basis for further studies on population genetics and phylogenetics.

The complete mitochondrial genome of Somanniathelphusa boyangensis and phylogenetic analysis of Genus Somanniathelphusa (Crustacea: Decapoda: Parathelphusidae).

In this study, the authors first obtained the mitochondrial genome of Somanniathelphusa boyangensis. The results showed that the mitochondrial genome is 17,032bp in length, included 13 protein-coding genes, 2 rRNAs genes, 22 tRNAs genes and 1 putative control region, and it has the characteristics of the metazoan mitochondrial genome A+T bias. All tRNA genes display the typical clover-leaf secondary structure except tRNASer(AGN), which has lost the dihydroxyuridine arm. The GenBank database contains the mitochondrial genomes of representatives of approximately 22 families of Brachyura, comprising 56 species, including 4 species of freshwater crab. The authors established the phylogenetic relationships using the maximum likelihood and Bayesian inference methods. The phylogenetic relationship indicated that the molecular taxonomy of S. boyangensis is consistent with current morphological classification, and Parathelphusidae and Potamidae are derived within the freshwater clade or as part of it. In addition, the authors used the COX1 sequence of Somanniathelphusa in GenBank and the COX1 sequence of S. boyangensis to estimated the divergence time of this genus. The result displayed that the divergence time of Somanniathelphusa qiongshanensis is consistent with the separation of Hainan Island from mainland China in the Beibu Gulf, and the divergence time for Somanniathelphusa taiwanensis and Somanniathelphusa amoyensis is consistent with the separation of Taiwan Province from Mainland China at Fujian Province. These data indicate that geologic events influenced speciation of the genus Somanniathelphusa.