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Food web topology and parasites in the pelagic zone of a subarctic lake
Article first published online: 13 JAN 2009
DOI: 10.1111/j.1365-2656.2008.01518.x
© 2009 The Authors. Journal compilation © 2009 British Ecological Society
Additional Information
How to Cite
Amundsen, P.-A., Lafferty, K. D., Knudsen, R., Primicerio, R., Klemetsen, A. and Kuris, A. M. (2009), Food web topology and parasites in the pelagic zone of a subarctic lake. Journal of Animal Ecology, 78: 563–572. doi: 10.1111/j.1365-2656.2008.01518.x
Publication History
- Issue published online: 31 MAR 2009
- Article first published online: 13 JAN 2009
- Received 31 August 2008; accepted 9 December 2008Handling Associate Editor: Andrew Beckerman
Keywords:
- connectance;
- ecological networks;
- linkage density;
- parasitism;
- trophic transmission
Summary
- 1Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web.
- 2Parasites used hosts at all trophic levels and increased both food-chain lengths and the total number of trophic levels. Their inclusion in the network analyses more than doubled the number of links and resulted in an increase in important food-web characteristics such as linkage density and connectance.
- 3More than half of the parasite taxa were trophically transmitted, exploiting hosts at multiple trophic levels and thus increasing the degree of omnivory in the trophic web.
- 4For trophically transmitted parasites, the number of parasite–host links exhibited a positive correlation with the linkage density of the host species, whereas no such relationship was seen for nontrophically transmitted parasites. Our findings suggest that the linkage density of free-living species affects their exposure to trophically transmitted parasites, which may be more likely to adopt highly connected species as hosts during the evolution of complex life cycles.
- 5The study supports a prominent role for parasites in ecological networks and demonstrates that their incorporation may substantially alter considerations of food-web structure and functioning.