DNA barcoding, phylogenetics, and morphometric analysis of various freshwater fishes

Abstract

Fish are diverse aquatic organisms, economically significant as a primary source of food and nutrients. Accurate species identification is crucial for conservation, taxonomy and management. This study combined morphological and COI gene-based approaches to identify and characterize fish diversity from three locations in Malakand Division, Khyber Pakhtunkhwa Pakistan. All species were identified morphologically. DNA was extracted using phenol-chloroform method followed by PCR and sequencing. The consensus sequences were then utilized as search queries in BLASTn. BioEdit was used for trimming and MEGA X for phylogenetic study. Fourteen specimens representing eight species (Tariqilabeo latius, Mastacembelus armatus, Tor putitora, Carassius auratus, Cyprinus carpio, Garra gotyla, Channa punctata and Channa gachua) from three orders were analyzed. Results showed AT (54.23%) and GC (45.77%) contents, and a high Simpson’s diversity index (0.925), indicating rich species presence and evenness. Density, relative density, frequency, relative frequency and morphometric measurements were also calculated. This study validates the effectiveness of integrating morphological and molecular identification using COI gene for fish species in the region, highlighting its potential for broader application. Biodiversity metrics provide insights into its distribution in the area. Our findings contribute to the understanding of fish diversity in Pakistan and inform conservation and management efforts.