Genetic diversity of the invading fish species Neogobius melanostomus [Pallas, 1811] [Gobiidae: Perciformes] from the Baltic Sea

The genetic diversity of Neogobius melanostomus populations was investigated by means of allozyme electrophoresis. 28 loci coding for 16 enzyme systems were examined. Samples originated from the Gulf of Gdańsk (Baltic Sea, newly founded population) and the north part of the Black Sea, off the Crimean Peninsula (centre of range). Despite their considerable geographical isolation, the genetic distance was not high (DNₑᵢ = 0.0353), also the populations had shown great similarity at the polymorphism level and the mean number of alleles per locus. High level of polymorphism and no signs of the founder effect in the Baltic Sea population could indicate that colonisation was very intensive.