Muskrat of Yakutia

Muskrat is an alien species for Yakutia, it appeared as a result of acclimation and quickly adapted: by the mid-90s of the last century it had inhabited all habitable reservoirs and became a key fur-harvesting species which ranks second after sable.During theadaptation process of the muskrat to the new climatic conditions of Yakutia, muskrats underwent some morphological, physiological and ecological changes.An importantecological feature of the Yakutian muskrat is the construction of a large number of forage huts and “vents” that it uses during long wintering, and as a result of a long-er period of existence under the ice and daily gnawing of a hole in the forage huts, the length of its facial part of the skull slightly decreased. Overwintered females during the breeding season can bring only 1-2 broods and this is less than in other parts of the range, but the muskrat is mostly infected by the trematode Quinqueserialis quinqueseriales of American origin, which was brought with the own-er during acclimation. Key words: Yakutia, muskrat, muskrat’s acclimation, muskrat’s adaptation, muskrat’s broods, helminthes.