DNA Barcoding as a Tool for Evaluating Genetic Diversity and Morphological Characteristics of Sparus aurata in Egypt

The Sparidae family, which includes commercially important breams and porgies within the Perciformes order, comprises various edible species of significant economic value. Sparus aurata, native to the Mediterranean Sea, constitutes a major portion of fishery production, particularly in the Alexandria and El-Max regions. This study combined traditional morphology-based species identification with DNA barcoding as a key complementary technique. This integrated approach also supports the evaluation of genetic diversity among different populations by analyzing the mitochondrial COI gene and D-loop region, alongside morphological characteristics. The research underscores the importance of investigating the population structure and genetic biodiversity of S. aurataacross four distinct sites along the Egyptian Mediterranean coast. In total, 69 out of 151 samples were analyzed using the mitochondrial COI gene, while 82 samples were analyzed using the D-loop region. Additionally, morphometric and meristic traits were recorded for 101 specimens collected from Al-Mahdiyyah. Phylogenetic trees based on genetic distance calculations were constructed for each molecular marker. The COI-based tree revealed two main genetic lineages (clades) comprising seven unique genetic forms (haplotypes). In contrast, the D-loop-based tree identified three clades encompassing twelve haplotypes. Recognizing their synergistic advantages, morphological analysis and DNA barcoding are employed together as an effective taxonomic approach for fish species identification. The data generated in this study will deepen our understanding of population connectivity and gene flow dynamics, and inform conservation strategies and fisheries management. Future research should explore the relationships between genetic diversity and life-history traits to further enhance conservation efforts.