Distribution and Dispersal of Parastenocarididae (Copepoda) in Northern Europe

Abstract

Five species of the mainly subterranean genus Parastenocaris Kessler (Copepoda) are found in northern Europe, viz. P. phyllura, P. glacialis, P. fontinalis, P. vicesima and P. brevipes. P. vicesima is marine, while P. phyllura occurs in fresh and brackish water and the other three are found solely in various fresh-water habitats. The two common species, P. phyllura and P. glacialis, exhibit different distribution patterns in the area investigated. P. phyllura is restricted to the area below the Highest Shore Line and its distribution is similar to the one displayed by some of the so-called glacial relicts of northern Europe. P. glacialis, on the other hand, is distributed all over Fennoscandia and occurs on Iceland and on Spitzbergen. P. phyllura occurs all along the coasts of the Baltic and its inland distribution is probably the result of its being left within the present distribution area during the lowering of the Baltic. P. glacialis is believed to have inhabited extensive areas in the protocratic era following ice regression. Beaches bordering lakes and rivers now exist as scattered and isolated remains of these areas. It is suggested that the species is strongly expansive and its endurance to low temperatures may have facilitated an immigration close to the retreating ice. Pe3I0Me