The use of mtCOI gene sequences in identifying species in the Southwest of Vietnam.

genus is characterised by their small body size and morphological variability, allowing them to adapt to different habitats. This paper analyses the mitochondrial cytochrome C oxidase subunit I gene sequences and morphology of for identification purposes and to understand genetic relationships. The morphological characteristics of differed obviously from and . After classification based on morphology, the total deoxyribonucleic acid of fish samples was isolated, and the mitochondrial cytochrome C oxidase subunit I genes were successfully amplified using the polymerase chain reaction method. At approximately 617bp, the obtained mitochondrial cytochrome C oxidase subunit I gene sequences were highly similar to the reference sequences on Genbank (85.90-100%). The phylogenetic graphic was divided into five distinct groups, where was grouped in one group; and and were grouped together. The results suggest that was an entirely different species from with a mean genetic divergence of up to 14%. However, further studies using a combination of other types of deoxyribonucleic acid barcoding together with morphological features should be undertaken to confirm these findings.