About the finding of Pallasiola quadrispinosa (G.O. Sars, 1867) (Gammaridae: Amphipoda) in Lake Vishtynetskoye (Kaliningrad region)

Lake Vishtynetskoye is the only water body in Kaliningrad region where the glacial freshwater relict Pallasiola quadrispinosa (G.O. Sars, 1867) inhabits. Amphipods were recorded in the littoral zone of the lake in autumn and winter 2008. In the biotope with silty shell limestone, amphipods were recorded only in winter (20 ind./m²). The abundance of P. quadrispinosa was 200 ind/m² in autumn and 60 ind/m² in the biotope of sand with overgrowths of water horsetail in winter. At present amphipod, P. quadrispinosa is registered in 12 lakes of Vishtynetsky (Suwalki) Upland.