Complete Mitochondrial Genome of (Odonata: Anisoptera: Chlorogomphidae) and Phylogenetic Analyses.

This study aimed to elucidate the mitochondrial genome organization of and the phylogenetic relationships of Chlorogomphidae. We used the Illumina MiSeq sequencing platform to sequence the mitochondrial genome of , which was subsequently assembled, annotated, and analyzed. Bayesian inference, maximum likelihood, and maximum parsimony methods were employed to construct the mitochondrial phylogenetic tree of 25 species of Chlorogomphidae based on and genes. We observed that the mitochondrial genome of is 15,251 bp in length and includes 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNA genes, and a non-coding control region. All PCGs start with a typical ATN codon. While , , , and end with an incomplete termination codon (T), the remaining PCGs terminate with TAG. The secondary structure of the 22 tRNAs showed that only the gene lacked the dihydrouracil arm (DHU arm), whereas the rest formed a typical cloverleaf structure. Additionally, 32 G-U mismatches were observed in the secondary structure. Phylogenetic analyses indicated that and are sister species. Divergence time analyses indicated that Chlorogomphidae originated around 111.04 Ma, with diverging from the common ancestor shared with approximately 58.51 Ma. This divergence is likely linked to the Paleocene-Eocene Thermal Maximum (PETM) and the tectonic uplift of the Himalayas, which created warm, humid habitats and contributed to geographic isolation. This study contributes to a better understanding of the mitochondrial genome and phylogeny of , providing valuable molecular markers for further genetic studies.