title: Host preference of an introduced 'generalist' parasite for a non-native host.
abstract: Parasites can invade new ecosystems if they are introduced with their native hosts or if they successfully infect and colonise new hosts upon arrival. Here, we ask to what extent an introduced parasite demonstrates specialisation among novel host species. Infection surveys across three field sites in Gatun Lake, Panama, revealed that the invasive peacock bass, Cichla monoculus, was more commonly infected by the introduced trematode parasite Centrocestus formosanus than were three other common cichlid fishes. Laboratory infection experiments were conducted to determine whether parasitism might be driven by differential encounter/exposure to parasites or by differential infection susceptibility/preference across different host species. These experiments were performed by controlling for parasite exposure in single host (compatibility) experiments and in mixed host (preference) experiments. In all cases, the peacock bass exhibited higher infection rates with viable metacercariae relative to the other potential fish hosts. Our experiments thus support that an introduced generalist parasite shows apparent specialisation on a specific novel host. Further studies are needed to determine whether these patterns of specialisation are the result of local adaptation following invasion by the parasite.
authors.affiliation: Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama; Department of Biology, McGill University, Montreal, Quebec, Canada. Electronic address: victor.frankel@mail.mcgill.ca.
authors.forename: Victor M
authors.initials: VM
authors.lastname: Frankel
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Hendry
authors.affiliation: Department of Biology, McGill University, Montreal, Quebec, Canada.
authors.forename: Gregor
authors.initials: G
authors.lastname: Rolshausen
authors.affiliation: Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancon, Panama.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Torchin
mesh_terms: D000818:Animals; D023681:Cichlids / Q000469:parasitology*; D006578:Heterophyidae / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D058507:Host Specificity; D010176:Panama
keywords: Biological invasions; Cichlid; Host preference; Host range; Host specificity; Host–parasite interactions; Introduced parasites; Trematode