The paper analyzes published and original data on the current distribution of alien species of malacostracan crustaceans including representatives from the orders Amphipoda, Mysidacea, Isopoda, Cumacea, and Decapoda in the Gulf of Finland (eastern part of the Baltic Sea). Thus far, 12 alien species of allochthonous origin have been recorded in this area. Also, seven species of malacostracans are known as actively spreading species in neighboring regions and therefore as potential invaders to the Gulf of Finland. The invasion history of the alien species and possible vector of their expansion from the original areas to the study area are discussed. |