title: The association of feeding behaviour with the resistance and tolerance to parasites in recently diverged sticklebacks.
abstract: Divergent natural selection regimes can contribute to adaptive population divergence, but can be sensitive to human-mediated environmental change. Nutrient loading of aquatic ecosystems, for example, might modify selection pressures by altering the abundance and distribution of resources and the prevalence and infectivity of parasites. Here, we used a mesocosm experiment to test for interactive effects of nutrient loading and parasitism on host condition and feeding ecology. Specifically, we investigated whether the common fish parasite Gyrodactylus sp. differentially affected recently diverged lake and stream ecotypes of three-spined stickleback (Gasterosteus aculeatus). We found that the stream ecotype had a higher resistance to Gyrodactylus sp. infections than the lake ecotype, and that both ecotypes experienced a cost of parasitism, indicated by negative relationships between parasite load and both stomach fullness and body condition. Overall, our results suggest that in the early stages of adaptive population divergence of hosts, parasites can affect host resistance, body condition and diet.
authors.affiliation: Center of Ecology, Evolution and Biogeochemistry, Aquatic Ecology Department, Eawag, Kastanienbaum, Switzerland. jaime.anaya-rojas@eawag.ch.|Center of Ecology, Evolution and Biogeochemistry, Department of Fish Ecology and Evolution, Eawag, Kastanienbaum, Switzerland. jaime.anaya-rojas@eawag.ch.|Division of Aquatic Ecology and Macroevolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland. jaime.anaya-rojas@eawag.ch.
authors.forename: Jaime M
authors.initials: JM
authors.lastname: Anaya-Rojas
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
authors.forename: Franziska S
authors.initials: FS
authors.lastname: Brunner
authors.affiliation: Center of Ecology, Evolution and Biogeochemistry, Aquatic Ecology Department, Eawag, Kastanienbaum, Switzerland.
authors.forename: Nina
authors.initials: N
authors.lastname: Sommer
authors.affiliation: Center of Ecology, Evolution and Biogeochemistry, Department of Fish Ecology and Evolution, Eawag, Kastanienbaum, Switzerland.|Division of Aquatic Ecology and Macroevolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.
authors.forename: Ole
authors.initials: O
authors.lastname: Seehausen
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, London, UK.
authors.forename: Christophe
authors.initials: C
authors.lastname: Eizaguirre
authors.affiliation: Center of Ecology, Evolution and Biogeochemistry, Aquatic Ecology Department, Eawag, Kastanienbaum, Switzerland.
authors.forename: Blake
authors.initials: B
authors.lastname: Matthews
mesh_terms: D000818:Animals; D004032:Diet; D060467:Disease Resistance; D005247:Feeding Behavior; D005393:Fish Diseases; D010271:Parasites; D023701:Smegmamorpha / Q000469:parasitology*; D014200:Trematoda / Q000472:pathogenicity
keywords: adaptive divergence; aquatic ecosystems; diet; environmental change; eutrophication; metabolic condition; parasites; three-spined stickleback; trade-offs