First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America

Variation in the intensity and prevalence of macroparasites in migratory caribou: a quasi-circumpolar study

Comparative studies across time and geographical regions are useful to improve our understanding of the health of wildlife populations. Our goal was to study parasitism in migratory caribou (Rangifer tarandus (L., 1758)) of North America and Greenland. A total of 1507 caribou were sampled across 12 herds to assess seven of their main helminth and arthropod macroparasites between 1978 and 2010. We sought to determine which factors such as sex, age class, herd size, and season best explained the prevalence and intensity of those parasites. Intensity of warble fly (Hypoderma tarandi (L., 1758)) larvae increased with age for males, whereas the opposite was observed in females. Prevalence of giant liver flukes (Fascioloides magna (Bassi, 1875) Ward, 1917), tapeworm Taenia hydatigena Pallas, 1766, and nose bot fly (Cephenemyia trompe (Modeer, 1786)) larvae was higher in adults than in calves. Prevalence of F. magna and T. hydatigena was higher at high herd size than at lower herd size. Greenland herds had the lowest prevalence of T. hydatigena and of the tapeworm Taenia krabbei Moniez, 1879, a higher intensity of H. tarandi, and a higher prevalence of C. trompe than the other herds. Of the herds from Quebec and Labrador, the Rivière-George herd had a higher prevalence of F. magna than the Rivière-aux-Feuilles herd. Our research provides the first comparative survey of these parasites of caribou across a broad spatial–temporal range.

Description and life-cycle of Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea)

A new species of tapeworm, Taenialynciscapreoli sp. n. (Cestoda, Cyclophyllidea), is described from the Eurasian lynx (Lynxlynx), the main definitive host, and the roe deer (Capreoluscapreolus and Capreoluspygargus), the main intermediate hosts, from Finland and Russia (Siberia and the Russian Far East). The new species was found once also in the wolf (Canislupus) and the Eurasian elk/moose (Alcesalces), representing accidental definitive and intermediate hosts, respectively. The conspecificity of adult specimens and metacestodes of Taenialynciscapreoli sp. n. in various host species and regions, and their distinction from related species of Taenia, was confirmed by partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 gene. Morphologically, Taenialynciscapreolisp. n. can be separated unambiguously from all other species of Taenia by the shape of its large rostellar hooks, particularly the characteristically short, wide and strongly curved blade. If the large rostellar hooks are missing, Taenialynciscapreoli may be separated from related species by a combination of morphological features of mature proglottids. It is suggested that Taenialynciscapreoli has been present in published materials concerning the tapeworms of Lynxlynx and Lynxpardinus in Europe, but has been misidentified as Taeniapisiformis (Bloch, 1780). Taenialynciscapreolisp. n. has not been found in lynx outside the range of roe deer, suggesting a transmission pathway based on a specific predator–prey relationship. The present study applies a novel, simple approach to compare qualitative interspecific differences in the shape of rostellar hooks.

Checklist of tapeworms (Platyhelminthes, Cestoda) of vertebrates in Finland

A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonusnylandicus Schneider, 1902 (a junior synonym of Diplocotyleolrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeidesfennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.

Helminths of grizzly bears (Ursus arctos) and American black bears (Ursus americanus) in Alberta and British Columbia, Canada

Between May 2011 and June 2013, we collected the carcasses and gastrointestinal tracts of 40 American black bears (Ursus americanus Pallas, 1780) and 13 grizzly bears (Ursus arctos L., 1758) from populations of Alberta and British Columbia, Canada. Specimens were examined for helminths, which were identified to the species level by applying an integrated morphological and molecular approach. Our goal was to investigate parasite biodiversity and infection parameters in the sampled grizzly and black bears. We found seven parasite taxa: Dirofilaria ursi Yamaguti, 1941, Baylisascaris transfuga (Rudolphi, 1819), Uncinaria rauschi Olsen, 1968, Uncinaria yukonensis (Wolfgang, 1956), Taenia arctos Haukisalmi, Lavikainen, Laaksonen and Meri, 2011, Diphyllobothrium dendriticum (Nitzsch, 1824), and Diphyllobothrium nihonkaiense Yamane, Kamo, Bylund and Wikgren, 1986. The statistical significance of infection prevalence, intensity, and abundance for each helminth species was assessed relative to host species, gender, age class, sampling season, and location. This is the first unequivocal report of the potentially zoonotic tapeworms D. dendriticum and D. nihonkaiense in North American bears. Furthermore, we provide insight into the biology and ecology of the nematodes B. transfuga, D. ursi, and species of Uncinaria Frölich, 1789, and enrich the information available on the recently described tapeworm T. arctos.