Analysis of mitochondrial DNA in Adriatic sardine (<i>Sardina pilchardus</i>): a preliminary study

Abstract

To determine the phylogenetic history of sardines researchers use mitochondrial DNA (mtDNA). Mitochondrial DNA contains highly informative polymorphic sites. The cytochrome b (cyt b) gene has been especially used by investigators because of its sufficient point mutation rate, enabling discrimination of closely related fish species, and determination of interspecific variability in pelagic fish species for population identification. Scientific surveys based on meristic, morphometric, and reproductive data suggested that two subpopulations of sardines coexisted in the Northern-Middle Adriatic Sea. Mitochondrial DNA analysis of sardines from the Adriatic Sea has never been conducted in the Republic of Croatia. This study included 14 sardine samples from three separate locations, as well as 30 different haplotype sequences retrieved from GenBank. The aim of this study was to determine the number of haplotypes in sardine populations from the Adriatic Sea, as well as to determine differences between populations. Mitochondrial DNA sequence analysis revealed 11 different haplotypes of sardines from the Adriatic Sea. The differences between samples from different locations were not scientifically significant, and the results of this study indicate homogeneity in the Adriatic sardine stock. However, three parsimony informative mutations found in our samples produce a clearly visible distinction between the Adriatic sardine samples and samples obtained from the seas adjacent to the Adriatic. This distinction of the Adriatic sardine samples can have applications in fisheries and fishery product quality testing.