Discernible but limited introgression has occurred where Trichinella nativa and the T6 genotype occur in sympatry

► Freeze resistant specimens of Trichinella spp. occur in the Canadian Arctic. ► They have been attributed to two taxa based on variation at one nuclear marker. ► That marker conflicts with evidence from maternally inherited DNA. ► Introgression has occurred where these parasites occur in sympatry. ► Multiple marker systems enhance evolutionary studies of Trichinella spp.