Cercopagis pengoi (Cladocera) conquered the southern Baltic Sea

The Ponto-Caspian cladocera Cercopagis pengoi invaded the Baltic Sea in 1992. For the first time it was recorded in the Gulf of Riga and three years later it appeared in the Gulf of Finland. In the summer of 1999 it had been also found in huge numbers in shallow areas (0.5 - 10 m) of the Gulf of Gdańsk