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dc.contributor.authorBudischak, Sarah Ashcomen_US
dc.date.accessioned2014-03-14T20:47:15Z
dc.date.available2014-03-14T20:47:15Z
dc.date.issued2007-10-16en_US
dc.identifier.otheretd-10302007-123149en_US
dc.identifier.urihttp://hdl.handle.net/10919/35534
dc.description.abstractTo examine the interactions of disease and pollution on amphibian populations around the world, I investigated the effect of infection on contaminant susceptibility in pickerel frog, Rana palustris, larvae. I conducted standard 48-hr toxicity tests to examine effect of trematode parasite, Echinostoma trivolvis, infection (0, 10, or 30 cercaria) on the susceptibility of pickerel frog tadpoles to the widely used organophosphate insecticide malathion. LC50 values ranged from 16.5 â 17.4 mg/L, within the range reported for other amphibian species. I found no differences in susceptibility to malathion among parasite treatments. Nevertheless, this crucial question remains to be tested in other amphibian host-parasite systems. Second, I studied the reverse interaction, the effect of pesticide exposure on susceptibility to parasite infection. I exposed pickerel frog embryos to low doses of malathion, then subjected morphologically normal tadpoles to E. trivolvis later in development. Malathion significantly decreased hatching success and viability rates at concentrations lower than previously documented for anuran embryos. After 7 wk of development in water with no malathion, tadpoles previously exposed to malathion as embryos suffered increased parasite encystment rates compared to controls. My research identifies embryonic development as a sensitive window and the potential for increased susceptibility to infection long after pesticide exposure has ceased. With potential for increased parasite prevalence from eutrophication and climate change, my data underscore the importance of understanding the reciprocal influences of parasites and pesticides in amphibians.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartBudischak4.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectsublethalen_US
dc.subjectlatenten_US
dc.subjecttrematodeen_US
dc.subjectacetylcholinesteraseen_US
dc.subjectmalathionen_US
dc.titleThe reciprocal influence of trematode parasites and malathion on developing pickerel frogs (Rana palustris)en_US
dc.typeThesisen_US
dc.contributor.departmentFisheries and Wildlife Sciencesen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineFisheries and Wildlife Sciencesen_US
dc.contributor.committeechairHopkins, William A.en_US
dc.contributor.committeememberBelden, Lisa K.en_US
dc.contributor.committeememberNeves, Richard J.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10302007-123149/en_US
dc.date.sdate2007-10-30en_US
dc.date.rdate2007-11-06
dc.date.adate2007-11-06en_US


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