The complete mitochondrial genome and phylogenetic analysis of scyphozoan jellyfish <i>Chrysaora chinensis</i> (Cnidaria: Scyphozoa: Pelagiidae) in the coastal sea of Fangchenggang, China

The scyphozoan jellyfish <i>Chrysaora chinensis</i> has been frequently observed in the coastal waters of Fangchenggang, China, in recent years. This study assembled and analyzed the first complete mitochondrial genome (mitogenome) of <i>C. chinensis</i> from next-generation sequencing data. The mitogenome was 16,783 bp in length, exhibited an overall AT content of 69%, and encoded 13 typical protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes (<i>rrnS</i> and <i>rrnL</i>), 2 transfer RNA (tRNA) genes (<i>trnW-tca</i> and <i>trnM-cat</i>), and an additional open reading frame (ORF), <i>dpo</i>. The mitochondrial gene order was largely consistent with that of previously reported jellyfish species. Furthermore, phylogenetic analysis of 13 mitochondrial PCGs from 19 jellyfish species indicated that <i>Chrysaora chinensis</i> is closely related to <i>Chrysaora pacifica</i> and <i>Chrysaora quinquecirrha</i>. These results provided a valuable reference for clarifying the taxonomy, evolutionary relationships, and phylogeography of scyphozoan jellyfish.