INVASION OF BRACKISH WATER HARPACTICOIDA <i>NITOCRA SPINIPES</i> (BOECK, 1865) (CRUSTACEA: COPEPODA: HARPACTICOIDA) INTO LAKE LADOGA
Since 2003 a new invasive species – brackish water harpacticoida Nitocra spinipes has begun to occur in the meiobenthic fauna composition of Lake Ladoga. Like most of similar introductions of non-native species its arrival is most likely connected to transfer of the ballast water by ships passing through the Volga-Baltic Waterway. The population density of these copepods at this stage is quite low and they are not found very often. But given the biological and ecological characteristics of the species, it should be expected an increase in this species number and its settling throughout the lake.