TAXONOMIC AND ECOLOGICAL IMPLICATIONS OF SHELL MORPHOLOGY OF 3 TESTACEANS (PROTOZOA, RHIZOPODA) IN RUSSIA AND CANADA

Morphological comparisons of shells of three testaceans, Trigonepyxis arcula, Nebela militaris, and Hyalosphenia papilio were made between a population in Russia and in Canada. Morphological differences were no ted in the shells of T. arcula sensu late, while no major differences in shell morphology were found in the latter two species. We suggest t hat the degree of variability, found in the two geographically isolate d populations of T. arcula sensu late indicates shell polymorphism. Sh ell polymorphism may complicate traditional taxonomic treatments which depend solely on morphological features of the shell.