Author
KUTZ, SUSAN - U SASKATCHEWAN CANADA | |
Hoberg, Eric | |
NISHI, JOHN - GOVT NW TERRITORIES | |
POLLEY, L - U SASKATCHEWAN CANADA |
Submitted to: Canadian Journal of Zoology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/25/2001 Publication Date: 12/24/2002 Citation: KUTZ, S.J., HOBERG, E.P., NISHI, J., POLLEY, L. DEVELOPMENT OF THE MUSKOX LUNGWORM, UMINGMAKSTRONGYLUS PALLIKUUKENSIS (PROTOSTRONGYLIDAE) IN GASTROPODS IN THE ARCTIC. CANADIAN JOURNAL OF ZOOLOGY. 2002. Interpretive Summary: Currently there are no empirical or model systems to evaluate the potential effects of global warming on host-parasite systems in ruminants, although changing climate has been predicted to have an impact on such complex assemblages, particularly in northern ecosystems. Field-based and laboratory studies were designed to examine patterns of development for parasitic nematodes and their linkage to temperature. We used an enclosure based system to examine the development of Umingmakstrongylus pallikuukensis, a protostrongylid lungworm of muskoxen, in Deroceras laeve, a slug intermediate host, in the Arctic. From June 1997 to July 1998, in a mesic sedge meadow near Kugluktuk, Nunavut, Canada, groups of experimentally infected slugs were placed in tundra enclosures. In 1997, larvae infecting slugs on or before 17 July developed to third stage larvae (L3) in 4-6 wk; larvae infecting slugs on 31 July or later did not develop to L3 before the end of September. Rates of larval development corresponde with those predicted from ambient surface temperatures, and threshold temperatures and degree days determined in the laboratory. Rates of development under scenarios of 2 C warming and cooling were modeled; predicted development times were decreased and increased by approximately 1 week, respectively. Climate change, especially in the Arctic, may alter patterns of parasite development and transmission, as well as the effects of parasites on host populations. Thus study system provides the first data for developing a predictive model to examine potential responses of a complex host-parasite system to global warming, and can be widely applied at both boreal and arctic latitudes. Technical Abstract: An enclosure based system was used to examine the development of Umingmakstrongylus pallikuukensis, a protostrongylid lungworm of muskoxen, in Deroceras laeve, a slug intermediate host. From June 1997 to July 1998, in a mesic sedge meadow near Kugluktuk, Nunavut, Canada, groups of 10 experimentally infected slugs were placed in tundra enclosures. In 1997, larvae infecting slugs on or before 17 July developed to third stage larva (L3) in 4-6 wk. Intensity of L3 in slugs peaked at 6-8 wk PI, and then progressively declined 10, 12 and 48-50 wk PI. L3 were most abundant in slugs during August: subsequently emerged L3 were found on vegetation. Larvae infecting slugs on 31 July or later did not develop to L3 before the end of September. First (L1) and second (L2) stage larvae, and L3 over- wintered in slugs. L1 and L2 completed development the following summer. Rates of larval development corresponded with those predicted from ambient surface temperatures, and threshold temperatures and degree days determine in the laboratory. Rates of development under scenarios of 2 C warming and cooling were modeled; predicted development times were decreased and increased by approximately 1 week, respectively. Climate change, especially in the Arctic, may alte patterns of parasite development and transmission, as well as the effects of parasites on host populations. |