DNA BARCODING AND GENETIC DIVERSITY OF THE CLUPEIDAE FISH FAMILY FROM THE FISH LANDING FACILITIES ACROSS THE COASTAL AREAS OF PAKISTAN - Mohsan Raza; Arif Muhammad Khan; Azhar Abbas Khan; Sumaira Aziz; Asma Mumtaz; Muhammad Irfan; Muhammad Ashfaq (Journal of Animal and Plant Sciences, 2026)
Species identification plays a paramount role in biodiversity assessment, ecological research, and fisheries management. The current work presents molecular-based identification of the Clupeidae fish family from the coastal waters of Pakistan, along with the first-ever record of the COI of Nematalosa arabica. Between 2019 and 2023, overall, 30 specimens belonging to the eight species were collected at two major fish landing facilities, Gwadar (Balochistan) and Karachi Fisheries Harbour (Karachi). The COI sequence analysis showed distinct intra- and interspecific genetic diversity, indicating the presence of a barcode gap among the analyzed taxa. Intraspecific genetic distances ranged from 0 to 1.53% among the individuals of Sardinella gibbosa, having the highest observed intraspecific divergence. Moreover, the highest interspecific divergence based on K2P distance was 25.4% between Tenualosa toli and Escualosa thoracata. Phylogenetic analysis grouped species based on their genetic relationships and was congruent with the taxonomic classification. Closely related species were grouped in well-supported sister clades, and morphologically similar species (e.g., T. toli and H. kelee) were well-resolved into separate clades. Eight haplotypes were identified in T. toli, suggesting possible regional haplotype structuring; however, due to limited and uneven sampling, these findings are preliminary and require validation with larger datasets. Overall, these findings confirm the use of COI-based DNA barcoding for species identification in Clupeidae and emphasize the need for broader geographic sampling and multi-locus studies for resolving population structure and evolutionary relationships.
Keywords: journal article; DNA barcoding; genetic diversity; COI gene; Species identification; vulnerable species