Mitogenomic Characterization and Phylogenetic Insights of the Ornamental Sail-Fin Molly (Poecilia velifera) in Non-Native Indonesian Waters.

The ornamental fish Poecilia velifera (Sail-fin molly, Poeciliidae) has spread widely to various non-native ecosystems around the world, far from its native habitat in the Yucatan Peninsula, Mexico. Despite the availability of some partial mitochondrial and nuclear genetic information, the complete mitogenomic structure and its variation remain unknown for this species, which is essential for a comprehensive genetic characterization and detailed phylogenetic investigation. This study applied next-generation sequencing to generate the de novo mitogenome of morphologically identified P. velifera from a non-native brackish water ecosystem in Banten Province, Indonesia. The resulting mitogenome was 16,627 bp in length and encompassed 13 protein-coding genes (PCGs), 22 transfer RNAs, two ribosomal RNAs, and a non-coding control region (CR). The result enhances our understanding of the genetic makeup of P. velifera compared to its congeners. Furthermore, the identified nucleotide variations within the conserved blocks of the CR region could provide insights into the functional role of this non-coding region. Bayesian phylogenetic inference using concatenated PCGs distinguished P. velifera from its congeners and showed monophyletic clustering of Poecilia in the family Poeciliidae, consistent with earlier evolutionary hypotheses. This first mitogenome of P. velifera paves the way for using multiple mitochondrial markers in species identification and understanding population structure in the near future. In addition, looking into the genetic evidence of this ornamental species in a non-native ecosystem, the study emphasizes the importance of strict quarantine regulations to protect Indonesia's native fish species.