title: First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America.
abstract: The cestode Taenia arctos was found at necropsy in the small intestine of a grizzly (Ursus arctos horribilis) and a black bear (Ursus americanus) from Kananaskis Country in southwestern Alberta, Canada. The autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit 1 gene confirmed their identity as T. arctos. This is the first report of T. arctos from definitive hosts in North America. Its detection in Canadian grizzly and black bears further supports the Holarctic distribution of this tapeworm species and its specificity for ursids as final hosts. Previously, T. arctos was unambiguously described at its adult stage in brown bears (Ursus arctos arctos) from Finland, and as larval stages in Eurasian elk (Alces alces) from Finland and moose (Alces americanus) from Alaska, USA. Given the morphological similarity between T. arctos and other Taenia species, the present study underlines the potential for misidentification of tapeworm taxa in previous parasitological reports from bears and moose across North America. The biogeographical history of both definitive and intermediate hosts in the Holarctic suggests an ancient interaction between U. arctos, Alces spp., and T. arctos, and a relatively recent host-switching event in U. americanus.
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada. Electronic address: ste.cata85@gmail.com.
authors.forename: Stefano
authors.initials: S
authors.lastname: Catalano
authors.affiliation: Canadian Cooperative Wildlife Health Centre - Alberta Node, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada.
authors.forename: Manigandan
authors.initials: M
authors.lastname: Lejeune
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada.
authors.forename: Guilherme G
authors.initials: GG
authors.lastname: Verocai
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada; Canadian Cooperative Wildlife Health Centre - Alberta Node, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada.
authors.forename: Pádraig J
authors.initials: PJ
authors.lastname: Duignan
mesh_terms: D000818:Animals; D002170:Canada / Q000453:epidemiology; D013621:Taenia / Q000145:classification* / Q000302:isolation & purification*; D013622:Taeniasis / Q000453:epidemiology / Q000469:parasitology / Q000662:veterinary*; D001503:Ursidae / Q000469:parasitology*
keywords: Nearctic; Taenia; Ursidae; cox1; mtDNA