Studies on the helminth fauna of Alaska. XI. Helminth parasites of microtine rodents-taxonomic considerations


Rausch, R.

Journal of Parasitology 38(5): 415-444

1952


Twenty-eight helminth species were recovered from 2, 078 microtine rodents collected in Alaska, northern Canada and Eurasia, and were examined by Rausch. The taxonomy of each species is discussed. Five belong to Paranoplocephala including P, lemmi n.sp. from the lemmings, Lemmus trimucronatus alascensis, L. t. trimucronatus and L. t. harroldi. It differs from P. infrequens in size of strobila, cirrus sac and egg, in the number of segments and testes and in the character of the uterus. The three species of Andrya recorded include A. arctica n.sp. from Dicrostonyx groenlandicus rubricaria. It is distinguished by its small, delicate strobila, relatively large cirrus sac and large eggs, and clearly belongs to the subgenus Aprostatandrya. On St. Lawrence Island there are hydatid infections in the voles Microtus oeconomus innuttus and Clethrionomys rutilus albiventer. On the mainland, natural infection of rodents is unknown and the natural intermediary is the moose. Rausch considers that there are at least six species of Echinococcus and intends to report on these later. Taenia crassiceps is recorded for the first time in North America.