Colonization of Europe by two American genetic types or species of the genus Marenzelleria (Polychaeta: Spionidae). An electrophoretic analysis of allozymes

Allozyme electrophoresis was conducted in an attempt to identify the origin of Marenzelleria sp. found in the North Sea and Baltic Sea. The analysis covered eight enzymes with ten loci from nine populations found on the North Atlantic coast, three populations in the North Sea and five populations in the Baltic Sea.