Indexed on: 25 Jan '17Published on: 25 Jan '17Published in: The Journal of parasitology
The ubiquity of host-parasite interactions and their potential for substantial representation, in terms of overall biomass, within ecosystems suggests that parasites have the capacity to influence energy flow within an ecosystem. While the influence of certain parasites on prey behavior has been well-documented, parasites could also exert an influence on ecosystem dynamics by influencing predator feeding behavior. The functional response of Tetragoneuria naiads was characterized by presenting naiads with varying abundances of Daphnia magna, after which a subset of the naiads were exposed to cercariae of Haematoloechus floedae, and the feeding trials repeated for both the control and exposed odonates. A type II functional response was chosen as an appropriate model for comparison. An indicator variable approach to nonlinear regression of the functional response data indicated that infected odonate naiads spent significantly more time foraging than they did prior to infection, whereas there was no significant change in the functional response of the control naiads. Infected odonates also had a slower rate of growth. These results imply a metabolic cost to infection of Tetragoneuria naiads by H. floedae that might is associated with the encapsulating response to the metacercariae that was observed in infected naiads.