Baltic Sea as species in 2005 and 2018 respectively, having formerly been confused with more widespread relatives. The tiny Copenhagen cockle ("Parvicardium hauniense"), a rare mussel, is sometimes considered endemic, but has now been recorded in the Mediterranean. However, some consider non-Baltic records to be misidentifications of juvenile lagoon cockles ("Cerastoderma glaucum"). Several widespread marine species have distinctive subpopulations in the Baltic Sea adapted to the low salinity, such as the Baltic Sea forms of the Atlantic herring and lumpsucker, which are smaller than the widespread forms in the North Atlantic. A peculiar feature of the fauna is that it contains a
History of Germans in Russia, Ukraine and the Soviet Union schools for expatriates living in the former Soviet Union are in operation. Russia: Georgia: Ukraine: The German presence on the eastern shores of the Baltic Sea dates back to the Middle Ages when traders and missionaries started arriving from central Europe. The German-speaking Livonian Brothers of the Sword conquered most of what is now Estonia and Latvia (the former Livonia) in the early 13th century. In 1237, the Brothers of the Sword were incorporated into the Teutonic Knights. During Peter the Great's rule Russia gained control over much of the Baltics from Sweden in the Great Northern War at the