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<DIV class=articleTitle xmlns="http://www.w3.org/1999/xhtml">
<DIV><STRONG>Journal of Ecology</STRONG></DIV>
<DIV id=publishedOnlineDate>Article first published online: 4 APR 2011</DIV>
<DIV class="citation articleInformationHeader" id=doi
xmlns="http://www.w3.org/1999/xhtml">DOI: 10.1111/j.1365-2745.2011.01837.x</DIV></DIV>
<DIV class=articleTitle xmlns="http://www.w3.org/1999/xhtml"> </DIV>
<DIV class=articleTitle xmlns="http://www.w3.org/1999/xhtml"><FONT
size=4>Non-consumptive predator effects indirectly influence marine plant
biomass and palatability</FONT></DIV>
<DIV class="citation articleInformationHeader" id=cr1
xmlns="http://www.w3.org/1999/xhtml">Pamela L. Reynolds<SUP>1,*,<A
href="http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2745.2011.01837.x/abstract#fn1"
shape=rect><FONT color=#007e8a>†</FONT></A></SUP>, Erik E.
Sotka<SUP>2</SUP></DIV>
<DIV class="citation articleInformationHeader"
xmlns="http://www.w3.org/1999/xhtml"><SUP>1</SUP> Department of Biology,
University of North Carolina, Chapel Hill, NC 27599, USA<SUP>2</SUP> Grice
Marine Laboratory, Department of Biology, College of Charleston, Charleston, SC
29412, USA Correspondence: Pamela L. Reynolds, E-mail: <!--TODO: clickthrough URL--><A title="Link to email address"
href="mailto:reynolds@vims.edu" shape=rect><FONT
color=#007e8a>reynolds@vims.edu</FONT></A></DIV>
<DIV class="citation articleInformationHeader"
xmlns="http://www.w3.org/1999/xhtml"> </DIV>
<DIV class="citation articleInformationHeader" id=additionalInformation
xmlns="http://www.w3.org/1999/xhtml">
<DIV style="CLEAR: left">
<DIV id=fn1><STRONG>Summary</STRONG></DIV></DIV></DIV>
<DIV id=productContent>
<DIV id=fulltext xmlns="http://www.w3.org/1999/xhtml">
<DIV id=abstract>
<DIV class=para>
<P><B>1.</B> Predators can reduce herbivory and increase plant biomass by
consuming herbivores, lowering individual herbivore feeding rates, or both. We
tested whether the presence of predators increases plant quality by
non-consumptively reducing grazing pressure and thereby weakening the strength
of the induced response in plant chemical defences.</P></DIV>
<DIV class=para>
<P><B>2.</B> We performed a 42-day outdoor mesocosm experiment in which the
herbivorous amphipod <EM>Ampithoe longimana</EM> was cultured on the brown
seaweed <EM>Sargassum filipendula</EM> in the presence and absence of olfactory
cues of its principal fish predator, the pinfish <EM>Lagodon rhomboides</EM>.
The presence of fish cues reduced per capita rates of amphipod grazing by nearly
50%. Over the span of the mesocosm experiment, this per capita reduction in
feeding rate yielded at least a 40% lower growth rate of amphipod populations
(i.e. <EM>r</EM> reduced from 1.01 to 0.61). The lower rates of amphipod grazing
(overall or per capita) correlated with higher algal biomass.</P></DIV>
<DIV class=para>
<P><B>3.</B> We pursued a series of laboratory-based feeding choice assays with
naïve amphipods to determine tissue palatability and the plant traits that
mediate feeding choices. Tissue from tanks without grazers was more palatable
than tissue from tanks with grazers, a pattern of induced plant defences that
has been documented previously. Surprisingly, however, plant tissue from tanks
with grazers and fish cues was more palatable than tissue from tanks with
grazers but without fish cues. All changes in algal palatability were mediated
by polar, but not lipophilic metabolites. These results suggest that the
non-consumptive effects of fish predators increases the food quality of
<EM>Sargassum</EM> by weakening the strength of its induced chemical
defences.</P></DIV>
<DIV class=para>
<P><B>4.</B><EM>Synthesis</EM>. The smell of predators has the potential to
regulate herbivore populations and affect the ecological dynamics of plant
biomass and chemical defences.</P></DIV></DIV></DIV></DIV></FONT></BODY></HTML>