The Dilution Effect In A Freshwater Mutualism

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Gretchen Lange Bailey (Creator)
Appalachian State University (ASU )
Web Site:
Robert Creed

Abstract: The dilution effect describes the effect of host diversity on parasite abundance—with greater host diversity, parasite levels per host are predicted to be lower, due to several possible mechanisms including a higher probability of parasites encountering non-competent hosts. No research has examined whether host dilution affects the prevalence of mutualistic symbionts on their hosts. Using the crayfish-branchiobdellidan worm mutualism, I performed an experiment investigating the effect of host density (1 vs 2 Cambarus chasmodactylus) and host diversity (1 C. chasmodactylus paired with 1 O. cristavarius) on branchiobdellidan(Cambarincola ingens) abundance. Worm numbers decreased over time on C. chasmodactylus alone and in the treatment in which it was paired with O. cristavarius, the latter being a poor host for C. ingens. Worm numbers declined the least in the 2 C. chasmodactylus treatment. While increased host diversity may reduce levels of parasitism (a positive effect of increased diversity) it could have negative effects on mutualistic symbionts depending on the quality of alternative hosts.

Additional Information

Honors Project
Bailey, G. (2017). "The Dilution Effect In A Freshwater Mutualism." Unpublished Honors Thesis. Appalachian State University, Boone, NC.
Language: English
Date: 2017
dilution effect, mutualism, crayfish, branchiobdellidan, symbiosis

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