Mitochondrial Control Region DNA Variation in Turbot Populations from the Bulgarian and Romanian Black Sea Coasts

The mitochondrial control region/CR/of 76 turbot specimens collected from the south and north Bulgarian and north Romanian regions of the west Black Sea coastal area was characterized. A total of 36 haplotypes were identified. Twenty-seven of these haplotypes were new and nine haplotypes were identical to previously reported Pmax haplotypes. The constructed haplotype parsimony network showed star-like phylogeny of the identified haplotypes, supporting the suggested Black Sea fish population bottleneck during the height of the last glacial period. The analysis of the haplotype sequences data did not provide clear indications on the existence of phylogeographic differentiation among the studied turbot populations inhabiting the west coast of the Black Sea. At the same time the haplotype phylogenetic analysis provided further support to the earlier proposed existence of two distinct turbot mitochondrial lineages, 'western Mediterranean 'and' eastern secluded Mediterranean basins'. The present study offers an essential background for long term monitoring of the changes of the Black Sea turbot populations.