{"id":{"repo_id":"lethbridge","oai_identifier":"oai:opus.uleth.ca:10133/6155"},"canonical_url":"https://search.dev.ndltd.org/etd/lethbridge/oai:opus.uleth.ca:10133/6155","repository":{"repo_id":"lethbridge","name":"University of Lethbridge","base_url":"https://opus.uleth.ca/server/oai/request"},"display":{"title":"Patterns of multiparasitism and consequences of co-infection in fathead minnows (Pimephales promelas)","abstract":"Individual hosts are often infected with multiple parasite species or strains simultaneously. Co-occurring parasites can profoundly impact each other and their hosts via interspecific interactions. To further our understanding of co-infection in wildlife, I censused the parasite communities of fathead minnows (Pimephales promelas) from southern Alberta over three years. Nearly all minnows were co-infected, and the larval trematodes Ornithodiplostomum ptychocheilus and Ornithodiplostomum sp. co-occurred more frequently than expected by chance. I exposed minnows to cercariae of these species to evaluate the effects of intensity dependence and co-infection on parasite development. While negative intensity-dependent growth occurred only for O. ptychocheilus, both species were significantly smaller post-encystment in co-infections than in mono-infections. Thus, Ornithodiplostomum spp. development is influenced by conspecifics and heterospecifics. Taken together, my results suggest that naturally co-occurring parasites in spatially segregated infection sites can influence one another’s growth within their shared intermediate host, with possible ecological and evolutionary consequences.","abstract_html":"Individual hosts are often infected with multiple parasite species or strains simultaneously. Co-occurring parasites can profoundly impact each other and their hosts via interspecific interactions. To further our understanding of co-infection in wildlife, I censused the parasite communities of fathead minnows (Pimephales promelas) from southern Alberta over three years. Nearly all minnows were co-infected, and the larval trematodes Ornithodiplostomum ptychocheilus and Ornithodiplostomum sp. co-occurred more frequently than expected by chance. I exposed minnows to cercariae of these species to evaluate the effects of intensity dependence and co-infection on parasite development. While negative intensity-dependent growth occurred only for O. ptychocheilus, both species were significantly smaller post-encystment in co-infections than in mono-infections. Thus, Ornithodiplostomum spp. development is influenced by conspecifics and heterospecifics. Taken together, my results suggest that naturally co-occurring parasites in spatially segregated infection sites can influence one another’s growth within their shared intermediate host, with possible ecological and evolutionary consequences.","abstract_has_math":false,"creators":["Hirtle, Sarah Valerie","University of Lethbridge. Faculty of Arts and Science"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021","date_published":"2021","updated_at":"2026-07-27T20:02:17Z","subjects":["ecology","parasitology","co-infection","parasitism","host-parasite interactions","trematoda","biodiversity","multiparasitism","multi-species infection","fish parasites","Fathead minnow--Parasites--Research","Fishes--Parasites","Parasites--Behavior--Research","Parasites--Ecology--Research","Host-parasite relationships","Trematoda--Research","Dissertations, Academic"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["hdl:10133/6155"],"render_values":[{"text":"hdl:10133/6155","href":null,"code":true}]}]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2021"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["ecology","parasitology","co-infection","parasitism","host-parasite interactions","trematoda","biodiversity","multiparasitism","multi-species infection","fish parasites","Fathead minnow--Parasites--Research","Fishes--Parasites","Parasites--Behavior--Research","Parasites--Ecology--Research","Host-parasite relationships","Trematoda--Research","Dissertations, Academic"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["hdl:10133/6155"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.other","label":"Dc Description Other","values":["Individual hosts are often infected with multiple parasite species or strains simultaneously. Co-occurring parasites can profoundly impact each other and their hosts via interspecific interactions. To further our understanding of co-infection in wildlife, I censused the parasite communities of fathead minnows (Pimephales promelas) from southern Alberta over three years. Nearly all minnows were co-infected, and the larval trematodes Ornithodiplostomum ptychocheilus and Ornithodiplostomum sp. co-occurred more frequently than expected by chance. I exposed minnows to cercariae of these species to evaluate the effects of intensity dependence and co-infection on parasite development. While negative intensity-dependent growth occurred only for O. ptychocheilus, both species were significantly smaller post-encystment in co-infections than in mono-infections. Thus, Ornithodiplostomum spp. development is influenced by conspecifics and heterospecifics. Taken together, my results suggest that naturally co-occurring parasites in spatially segregated infection sites can influence one another’s growth within their shared intermediate host, with possible ecological and evolutionary consequences."]},{"key":"dc:title","label":"Title","values":["Patterns of multiparasitism and consequences of co-infection in fathead minnows (Pimephales promelas)"]}]}],"canonical_facts":{"dc:date.issued":["2021"],"dc:description.other":["Individual hosts are often infected with multiple parasite species or strains simultaneously. Co-occurring parasites can profoundly impact each other and their hosts via interspecific interactions. To further our understanding of co-infection in wildlife, I censused the parasite communities of fathead minnows (Pimephales promelas) from southern Alberta over three years. Nearly all minnows were co-infected, and the larval trematodes Ornithodiplostomum ptychocheilus and Ornithodiplostomum sp. co-occurred more frequently than expected by chance. I exposed minnows to cercariae of these species to evaluate the effects of intensity dependence and co-infection on parasite development. While negative intensity-dependent growth occurred only for O. ptychocheilus, both species were significantly smaller post-encystment in co-infections than in mono-infections. Thus, Ornithodiplostomum spp. development is influenced by conspecifics and heterospecifics. Taken together, my results suggest that naturally co-occurring parasites in spatially segregated infection sites can influence one another’s growth within their shared intermediate host, with possible ecological and evolutionary consequences."],"dc:identifier":["hdl:10133/6155"],"dc:subject":["ecology","parasitology","co-infection","parasitism","host-parasite interactions","trematoda","biodiversity","multiparasitism","multi-species infection","fish parasites","Fathead minnow--Parasites--Research","Fishes--Parasites","Parasites--Behavior--Research","Parasites--Ecology--Research","Host-parasite relationships","Trematoda--Research","Dissertations, Academic"],"dc:title":["Patterns of multiparasitism and consequences of co-infection in fathead minnows (Pimephales promelas)"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T20:02:17Z"}