The biogeography of the caribou lungworm, (Nematoda: Protostrongylidae) across northern North America.

(Nematoda; Protostrongylidae) is a recently described species of lungworm that infects caribou (), muskoxen () and moose () across northern North America. Herein we explore the geographic distribution of through geographically extensive sampling and discuss the biogeography of this multi-host parasite. We analyzed fecal samples of three caribou subspecies (n = 1485), two muskox subspecies (n = 159), and two moose subspecies (n = 264) from across northern North America. Protostrongylid dorsal-spined larvae (DSL) were found in 23.8%, 73.6%, and 4.2% of these ungulates, respectively. A portion of recovered DSL were identified by genetic analyses of the ITS-2 region of the nuclear rDNA or the cytochrome oxidase c subunit I (COI) region of the mtDNA. We found widely distributed among caribou and muskox populations across most of their geographic prange in North America but it was rare in moose. was present in caribou and moose and we provide new geographic records for this species. This study provides a substantial expansion of the knowledge defining the current distribution and biogeography of protostrongylid nematodes in northern ungulates. Insights about the host and geographic range of can serve as a geographically extensive baseline for monitoring current distribution and in anticipating future biogeographic scenarios under a regime of accelerating climate and anthropogenic perturbation.