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 noted in the shells of T. arcula sensu late, while no major differences in shell morphology were found in the latter two species. We suggest that the degree of variability, found in the two geographically isolated populations of T. arcula sensu late indicates shell polymorphism. Shell polymorphism may complicate traditional taxonomic treatments which depend solely on morphological features of the shell.