The ornamental fish sector is a widespread and global component of international trade, fisheries,
aqu aculture and developm e nt. The utilization of multiple trade names causes problem in species
identification. Moreover, unmanaged trading could lead to severe threats to biodiversity. In this
regard, DNA barcoding could effectively clarify the divergence of the species. Consider i ng the utility
of DNA barcoding as a comprehensive system for species identification and discovery, this study aims
to investigate the genetic relationship and to construct the phylogenetic tree among those selected fish
species colle cted from selected pe t stores in Seremban, Negeri Sembilan. The 642bp barcode
fragment of the Cytochrome c oxidase I ( COI ) gene was PCR amplified. Results from BLAST
showed all the generated sequence were subjected to high percentage identity index and sim ilarity
between 99% t o 100%. It was then analyzed using MEGA 7.0 through Neighbour Joining (NJ)
clustering and K2P distance based approach. The analysis revealed straightforward identification of
eight specimens into five species with increasing value of g enetic distances from conspecific (0.05%)
to the taxonomic level (20.18%). The phylogenetic analysis consists of own sequences and reference
sequences obtained from the GenBank. All the specimens from different genus was found with high
bootstrap value (n> 90%) through Neighbou r Joining (NJ) and Maximum Likelihood method. Thus,
DNA barcoding reflects the efficacy of the techniques in identifying the genetic assessment in selected
ornamental fishes.