Complex phylogeographic relationships among the Eurasian perch (Perca fluviatilis) populations in the eastern part of the Baltic Sea Region

The Eurasian perch (Perca fluviatilis) is an economically and environmentally important fish. Its distribution is changing because of many anthropogenic factors, including aquaculture and restocking. Careless dislocations enhance risk disrupt the established geographical genetic structure of this species. Set as a benchmark for future studies, this paper investigates the current perch status in the Baltic Sea Region. It presents the genetic diversity and phylogeographic relationships among 19 perch populations in Lithuania, Latvia and Belarus, on the basis of 489 perch sequences of the mtDNA D-loop region. Analysis of molecular data revealed that in the eastern part of the Baltic Sea Region, the genetic diversity of mtDNA D-loop of the perch was greater and different in comparison to that from other European locations. Based on SAMOVA results, perch samples were divided into four genetically distinct groups (I–IV). These groups indicate non-casual geographical distributions of genetically differentiated perch populations in Lithuania, Latvia and Belarus. The colonisation of the eastern part of the Baltic during the last deglaciation period resulted in perch populations that are genetically more complex than anticipated. The just-assessed current perch genetic diversity may be useful for monitoring its changes induced by growing anthropogenic activities in the Baltic Sea Region.