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Climate Change and the Muskox Nematode Biology 3700 Emilie Ontko March 23 rd 2011.

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Presentation on theme: "Climate Change and the Muskox Nematode Biology 3700 Emilie Ontko March 23 rd 2011."— Presentation transcript:

1 Climate Change and the Muskox Nematode Biology 3700 Emilie Ontko March 23 rd 2011

2 Nematode Umingmakstrongylus pallikuukensis Large protostrongylid lungworm Dioeceous Forms large cysts deep in the lungs Discovered in Nunavut in 1988

3 Novel Parasite or New Discovery No historical baseline for parasites Not a recent host switch Reasons for non-detection before 1988: –Low infection levels –Minimal contact between people and Muskox –Hunters discard lungs –Cysts mistaken for hydatid cysts –Highly restricted range Only detected by luck after follow-up of death of a radio-collared individual

4 Life Cycle

5 Life Cycle Facts Pre-patency period ~91-95 days Patent period > 22 months L3 larvae ingested during summer Takes two years to mature from L1-L3 in gastropod host Migration route from GI tract to lungs not known Cysts: tough, grey and well defined –Contain at least 1 male, 1 gravid female, free eggs and L1 larvae

6 Experimental Results 1999: Prevalence up to 92% of L1 in fecal samples –Up to 258 cysts in one animal 2004: Prevalence of infection  100% –Intensity  >100 cysts/animal

7 Hypotheses on Pathology No clinical sign of pathology In established infections pathology is limited to the cysts Inflammatory response and small lesions found in developing infection Exercise intolerance

8 Hypotheses on Pathology Caused by displacement and compression of alveoli and lung spaces Infected animals move slower and have been reported to bleed from the nostrils Predators prey on slow moving animals Exercise intolerance may be significant

9 Other Definitive Hosts Investigations of parasite with: –Domestic Sheep –Dall’s sheep –Sympatric moose –Sympatric caribou Restricted to Muskox Post mortem Dall’s sheep: no encysted or living parasites, but legions on liver and lungs

10 Climate Change Significant and unprecedented warming in West- Central Canadian Arctic and Subarctic –Increase of an average of 2.0 degrees Earlier springs and later autumns

11 Effect on Muskox Warmer summers larvae can develop from L1-L3 within the summer Longer summer increase chance that larvae can develop to L3 in one summer 50% decline in population in infected areas, other areas increased significantly (Studied 1988-1994)

12 Future Worries Spread to areas with suitable gastropod host Prevalence of infection in all infected populations will increase Possible host switch to more domesticated and utilized host Switch of other ungulate parasites to Muskoxen

13 References Kutz, S.J., Hoberg, E.P., and Polley, L. Experimental infections of muskoxen (Ovibos moschatus) and domestic sheep with Umingmakstrongylus pallikuukensis (Nematoda:Protostrongylidae): parasite development, population structure, and pathology. Canadian Journal of Zoology; Oct 1999. 77(10): 1562-1572 Kutz, S.J., Hoberg, E.P., Nagy, J., Polly, L. and Elkin, E. “Emerging Parasitic Infections in Arctic Ungulates. Integrative and Comparative Biology, Apr. 2004. 44(2): 109-118 Kutz, S., Garde, E., Veitch, A., Nagy, J., Ghandi, F., and Polly, L. Muskox Lungworm (Umingmakstrongylus pallikuukensis) does not establish in experimentally exposed thinhorn sheep (Ovis dalli). Journal of Wildlife Diseases, 2004. 40(2): 197-204 s.htm

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