Title:
Prey nutritional quality interacts with chemical defenses to affect consumer feeding and fitness

dc.contributor.author Cruz-Rivera, Edwin en_US
dc.contributor.author Hay, Mark E. en_US
dc.contributor.corporatename University of North Carolina at Chapel Hill. Institute of Marine Sciences en_US
dc.contributor.corporatename Georgia Institute of Technology. School of Biology en_US
dc.date.accessioned 2011-01-28T17:28:36Z
dc.date.available 2011-01-28T17:28:36Z
dc.date.issued 2003-08
dc.description DOI: 10.1890/0012-9615(2003)073[0483:PNQIWC]2.0.CO;2
dc.description © Ecological Society of America en_US
dc.description.abstract Numerous studies have assessed the individual effects of prey nutritional quality or chemical defenses on consumer feeding behavior. However, little is known about how these traits interact to affect consumer feeding and performance. We tested the separate and interactive effects of prey chemical defenses and nutritional quality on the feeding behavior and fitness of six sympatric crustacean mesograzers. Natural concentrations of diterpene alcohols (dictyols) from the brown alga Dictyota menstrualis were incorporated, or not incorporated, into lower quality and higher quality foods to create artificial diets mimicking prey of variable value and defense. Five amphipods (Ampithoe longimana, A. valida, Cymadusa compta, Gammarus mucronatus, and Elasmopus levis) and one isopod (Paracerceis caudata), representing a continuum of closely to distantly related organisms, were fed intact algae or lower and higher quality diets containing or lacking dictyols. All six mesograzers preferred the green alga Enteromorpha intestinalis to the dictyol producing alga Dictyota menstrualis. In assays allowing consumers to choose between simultaneously available foods, dictyols deterred feeding by all five amphipods, but not the isopod; this occurred for both lower and higher quality foods. In no-choice assays, where consumers were confined with only one of our four treatment diets, effects on feeding became more complex. Nutritional quality alone affected feeding by five of the six species. These grazers compensated for lower quality by increasing consumption. Dictyols suppressed feeding for four of the six species. More interestingly, there were significant dictyol × quality interactions for three species. Dictyols decreased feeding more when placed in lower quality foods than higher quality foods. Two amphipods deterred by dictyols in the choice assays readily consumed dictyol-containing foods in no-choice situations and suffered few negative effects of doing so. Although all amphipods were deterred by dictyols in choice assays, dictyols decreased fitness (survivorship, growth, or reproduction) for only four of the five species. These effects included large and immediate decreases in survivorship, dramatic effects on reproduction, and modest effects on female growth. Dictyols enhanced survivorship of the isopod. Thus, the effects of secondary metabolites on feeding in choice situations vs. fitness in long-term assays were inconsistent. For three amphipods, certain effects of food quality, dictyols, or their interaction were detected only for females. In general, negative effects of dictyols on fitness were greater in lower than in higher quality foods, suggesting that prey nutritional value may counteract the effects of defensive metabolites. For example, when G. mucronatus consumed dictyols in lower quality foods, mortality was >80% by day 5; for dictyols in higher quality foods, 80% mortality took 28 days to develop. Lower quality foods alone significantly decreased growth for the isopod, three of the amphipods, and the females of a fourth amphipod, concomitantly reducing fecundity for four of the five amphipods studied. The effects of both chemical defenses and nutritional quality were unrelated to consumer phylogeny; responses of congeners varied as much, or more, than responses of more distantly related consumers. Understanding mechanisms and consequences of food selection requires that the interactive effects of both chemical defenses and prey nutritional characteristics be considered explicitly. en_US
dc.identifier.citation Cruz-Rivera, Edwin, and Mark E. Hay. 2003. Prey nutritional quality interacts with chemical defenses to affect consumer feeding and fitness. Ecological Monographs 73:483–506. en_US
dc.identifier.doi 10.1890/0012-9615(2003)073[0483:PNQIWC]2.0.CO;2
dc.identifier.issn 0012-9615
dc.identifier.uri http://hdl.handle.net/1853/36752
dc.language.iso en_US en_US
dc.publisher Georgia Institute of Technology en_US
dc.publisher.original Ecological Society of America
dc.subject Amphipods en_US
dc.subject Ampithoe en_US
dc.subject Chemical defenses and consumer food choice en_US
dc.subject Compensatory feeding en_US
dc.subject Cymadusa en_US
dc.subject Dictyota en_US
dc.subject Elasmopus en_US
dc.subject Gammarus en_US
dc.subject Isopods en_US
dc.subject Nutritional interactions with chemical defenses en_US
dc.subject Paracerceis en_US
dc.subject Prey defense and value affect consumer fitness en_US
dc.title Prey nutritional quality interacts with chemical defenses to affect consumer feeding and fitness en_US
dc.type Text
dc.type.genre Article
dspace.entity.type Publication
local.contributor.author Hay, Mark E.
local.contributor.corporatename College of Sciences
local.contributor.corporatename School of Biological Sciences
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relation.isOrgUnitOfPublication 85042be6-2d68-4e07-b384-e1f908fae48a
relation.isOrgUnitOfPublication c8b3bd08-9989-40d3-afe3-e0ad8d5c72b5
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