摘要：The invasive ctenophore Mnemiopsis leidyi is expanding its range in the Baltic Sea. It was observed in the Landsort Deep in March 2007 and in the western part of the Gulf of Finland, �land and Bothnian Seas in August 2007. In September the abundances were several times higher in the Gulf of Finland and the �land Sea than in August, maximum abundances being 694 ind m -2 , and densities 24 ind m -3 . In December M. leidyi was observed also in the eastern Gulf of Finland at low abundances. Eggs and newly hatched larvae as well as juvenile stages were observed during autumn, indicating efficient reproduction and establishment of the species in the northern Baltic Sea.
关键词：Mnemiopsis leidyi;Baltic Sea;range expansion;reproduction;invasive species
