Recent molecular approaches have revolutionized the world of species classification and identification. In this study, we delved into the fascinating domain of DNA barcoding precisely for rare marine species and delineated species population genetic variability, genetic differences, and phylogenetic relationships between families/genera. 542 COI sequences from experimental species and an online database were considered for phylogenetic and Fst analysis. Moreover, an online QR code generator was used to develop the first-ever QR codes for nucleotide information of these species. It is the first study from Pakistan to reveal the barcode gap, phylogenetic relationship, and genetic diversity of the fish species in the northern Arabian Sea. A notable genetic variation level was revealed, with the highest value of 0.75 indicating a significant differentiation between populations of Taiwan and Pakistan. In contrast, the lowest Fst value of 0.04 manifested minimal genetic differentiation between populations in the USA and Bangladesh. An average genetic distance using the Kimura 2 parameter (K2P) model using BOLD systems revealed 20.17 and 19.87 percent within genus and family respectively. Nevertheless, this study documented the COI sequence of Caesio varilineata and Uranoscopus dollfusi, for the first time. The combined use of taxonomy, DNA barcoding, and QR codes appeared to be robust approaches, and have paved the way for a better understanding of fishes rarely found in Pakistan, northern Arabian Sea.
Novelty Statement | This study demonstrates the utility of integrating DNA barcoding and QR coding for elucidating the genetic diversity and phylogenetic relationships of rare marine fish species in the northern Arabian Sea, thereby enhancing our understanding of this previously undercharacterized region.