Shrews of the Nadym River Basin (north of Western Siberia)

The habitation of four species of shrews—Sorex tundrensis Merriam, 1990, S. caecutiens Laxmann, 1788; S. minutissimus Zimmermann, 1780; and S. minutus Linnaeus, 1766—has been determined in the Nadym River basin. Data on reproduction, age, and sex structure and nutrition and helminths (nematodes) are given. In underyearlings of the tundra shrew, the double prevalence of females over males is fixed. At present, for the nematode Soboliphyme jamesoni, the Nadym basin is identified by the western border of its distribution.