Context dependency of infectious disease: the cyanobacterium Microcystis aeruginosa decreases white bacterial disease in Daphnia magna. (19th December 2013)

• Record Type: Journal Article
• Authors: Coopman, Marlies; Muylaert, Koenraad; Lange, Benjamin; Reyserhove, Lien; Decaestecker, Ellen
• Is Part Of: Freshwater biology. Volume 59:Number 4(2014:Apr.)
• Page Start: 714
• Page End: 723
• Publication Date: 2013-12-19
• Subjects: Freshwater biology -- Periodicals; Biologie d'eau douce -- Périodiques; 577.605
• DOI: 10.1111/fwb.12298
• Languages: English
• ISSNs: 0046-5070

Abstract

<abstract abstract-type="main" id="fwb12298-abs-0001"> <title>Summary</title> <p> <list id="fwb12298-list-0001" list-type="order"> <list-item> <p>We investigate whether an increase in the occurrence of cyanobacterial blooms affects zooplankton–parasite interactions. Cyanobacteria are expected to be of poor food quality for zooplankton hosts and are therefore expected to increase parasitism. Nevertheless, simultaneous exposure to both stressors may lead to different results, given the antibacterial secondary metabolites of cyanobacteria.</p> </list-item> <list-item> <p>We exposed the zooplankter <italic>Daphnia magna</italic> to the cyanobacterial species <italic>Microcystis aeruginosa</italic> and the parasite that causes white bacterial disease in <italic>D. magna</italic>. Increased <italic>M. aeruginosa</italic> concentrations reduced the percentage of infected individuals and as such protected <italic>D. magna</italic> against parasitism. Interactions between <italic>M. aeruginosa</italic> and the parasite were antagonistic in terms of percentage of surviving <italic>Daphnia</italic>, total offspring per female and clutch size. Additional plating experiments showed a direct negative effect of <italic>Microcystis</italic> on bacterial growth.</p> </list-item> <list-item> <p>The results suggest that changes in phytoplankton affect host–parasite interactions in zooplankton. Contrary to the prevailing paradigm that multiple stressors often induce additive or synergistic effects, we report an antagonistic effect of the presence of cyanobacterial stress on parasites in <italic>Daphnia</italic>. Thus, assessment of the outcome of host–parasite interactions needs to incorporate the environmental context.</p> </list-item> </list> </p> </abstract>