Genetic Variation of Clupeonella engrauliformis Populations Inferred from RFLP Analysis of Mitochondrial DNA D-loop Region on the Southern Coast of the Caspian Sea, Iran

Analysis of the genetic structure of the Clupeonella engrauliformis, one of the bony fish species, with high commercial value, was undertaken to gain information regarding the differentiation of this species from two distinct geographical areas (Anzali and Amirabad) located at the western and eastern parts of the Southern Caspian Sea, Iran. Restriction fragment length polymorphism (RFLP) analysis was performed on PCR amplified DNA fragments containing the D-loop region of the C. engrauliformis mito-chondrial DNA. A total of 100 individuals collected from two areas were surveyed with 18 endonucleases. Six out of 18 enzymes were polymorphic yielding a total of 12 com-posite haplotypes. Chi-square tests showed significant results in haplotype frequencies among populations and analysis of molecular variance (AMOVA) tests indicated that most of the variation was due to within populations (98.8 %) with FST= 0.01172. Despite the existence of significant differentiation between haplotypes for mtDNA variation, no consistent pattern of genetic structuring was revealed and nucleotide divergence among C. engrauliformis populations was low. The results indicated that different genotypes exist in these areas, resulting in identification of genetic stocks of C. engrauliformis. Therefore, careful attention must be given to these matters for the effective cultivation, management and protection of C. engrauliformis stock on the Southern coast of the Caspian Sea.