DNA Barcoding of Eight Freshwater Fish Species (Order Siluriformes) From the River Ravi, Pakistan

Pakistan's freshwater bodies host significant fish species, but molecular identification is still in its infancy, necessitating the use of morphological and molecular DNA barcoding techniques. The study confirmed the species of the order Siluriformes found in the River Ravi, Pakistan, using DNA extracted from muscle tissue, sequenced for the COI gene, and obtained accession and Barcode Index Numbers from GenBank and BOLD databases. In the BLAST search, identities ranged from 99.23–100% and 99.52–100% in the GenBank and BOLD databases, respectively. The study revealed that the Kimura 2-Parameter genetic distance increased from lower to higher taxonomic levels: within species (0.00%) < within genus (15.17%) < within family (19.77%). The study estimated average nucleotide differences (104.964) and nucleotide diversity (0.16099) but found Tajima's neutrality test to be statistically insignificant. The neighbor-joining tree displayed closely linked species under a node, whereas divergent species were grouped under distinct nodes. The COI gene-based DNA barcoding aids in Pakistan's fish resource inventory, monitoring, and management, providing valuable input for traditional methods.