Helminth parasites of fisher Martes pennanti (Erxleben) from Manitoba, Canada.

Seven species of helminths were recovered during a survey of 162 fisher (Martes pennanti) from four areas of Manitoba: Baylisascaris devosi in 52 fisher; Taenia sibirica in 25; Physaloptera sp. in nine; Alaria mustelae in two; Metorchis conjunctus in one; Trichinella spiralis in one of 81; Molineus sp. in one. B. devosi was the most prevalent parasite and differences in its geographical distribution were possibly related to population density of fisher. The prevalence of other parasites did not appear to be related to density of fisher.