DNA Barcoding Reveals the Genetic Identity of Licorice Gourami Parosphromenus deissneri, an Endangered Species Threatened by Tin Mining in Bangka

Parosphromenus deissneri, an endangered ornamental freshwater fish endemic to Bangka Island, Indonesia, has experienced a drastic decline in population due to habitat degradation, particularly from tin mining activities. Accurate species identification is crucial in supporting conservation efforts, especially in taxonomic groups that are complex or morphologically similar (cryptic). This study aimed to characterize P. deissneri molecularly using the mitochondrial cytochrome c oxidase subunit 1 (co1) gene. A co1 fragment of approximately 650 base pairs was successfully amplified and sequenced. BLAST and BOLD analyses revealed high similarity (>98%) with the reference sequence of P. deissneri. Genetic distance analysis using the Kimura 2-parameter model indicated low intra-species divergence (0.000–0.008), while inter-species distances were significantly higher: 0.183–0.197 with P. quindecim and 0.121–0.142 with P. nagyi. Phylogenetic reconstruction using the neighbor-joining and maximum likelihood methods yielded similar topologies, with all specimens clustering within the monophyletic clade of P. deissneri. These results confirm the validity of co1-based DNA barcoding for species identification and provide molecular insights into evolutionary patterns within the genus Parosphromenus. Further research is recommended to use additional genetic markers and a broader geographical coverage to evaluate the potential for local population variation and support more precise conservation strategies.