Owing to its extremely long life span and occurrence in the entire North Atlantic, the Arctic boreal Arctica islandica has become of particular significance for monitoring the environment, because information on past environmental conditions is archived in morphological and biogeochemical properties of the calcareous shell. To evaluate whether such properties are comparable between different localities, shell and soft body morphometry of six A. islandica populations, Norwegian Coast, Kattegat, Kiel Bay (Baltic), White Sea, German Bight (North Sea), and off NE Iceland, were compared. Discriminant analysis indicated distinct differences between populations, albeit not related to geographical distance, but more likely to local hydrography, bottom morphology, and food regime.