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Seasonal Trophic Niche Shift and Cascading Effect of a Generalist Predator Fish

Xu, Jun; Wen, Zhourui; Gong, Zhijun; Zhang, Min; Xie, Ping and Hansson, Lars-Anders LU (2012) In PLoS ONE 7(12).
Abstract
Few studies have examined how foraging niche shift of a predator over time cascade down to local prey communities. Here we examine patterns of temporal foraging niche shifts of a generalist predator (yellow catfish, Pelteobagrus fulvidraco) and the abundance of prey communities in a subtropical lake. We predicted that the nature of these interactions would have implications for patterns in diet shifts and growth of the predator. Our results show significant decreases in planktivory and benthivory from late spring to summer and autumn, whereas piscivory increased significantly from mid-summer until late autumn and also increased steadily with predator body length. The temporal dynamics in predator/prey ratios indicate that the predation... (More)
Few studies have examined how foraging niche shift of a predator over time cascade down to local prey communities. Here we examine patterns of temporal foraging niche shifts of a generalist predator (yellow catfish, Pelteobagrus fulvidraco) and the abundance of prey communities in a subtropical lake. We predicted that the nature of these interactions would have implications for patterns in diet shifts and growth of the predator. Our results show significant decreases in planktivory and benthivory from late spring to summer and autumn, whereas piscivory increased significantly from mid-summer until late autumn and also increased steadily with predator body length. The temporal dynamics in predator/prey ratios indicate that the predation pressure on zooplankton and zoobenthos decreased when the predation pressure on the prey fish and shrimps was high. Yellow catfish adjusted their foraging strategies to temporal changes in food availability, which is in agreement with optimal foraging theory. Meanwhile the decrease in planktivory and benthivory of yellow catfish enabled primary consumers, such as zooplankton and benthic invertebrates, to develop under low grazing pressure via trophic cascading effects in the local food web. Thus, yellow catfish shifts its foraging niche to intermediate consumers in the food web to benefit the energetic demand on growth and reproduction during summer, which in turn indirectly facilitate the primary consumers. In complex food webs, trophic interactions are usually expected to reduce the strength and penetrance of trophic cascades. However, our study demonstrates strong associations between foraging niche of piscivorous fish and abundance of prey. This relationship appeared to be an important factor in producing top-down effects on both benthic and planktonic food webs. Citation: Xu J, Wen Z, Gong Z, Zhang M, Xie P, et al. (2012) Seasonal Trophic Niche Shift and Cascading Effect of a Generalist Predator Fish. PLoS ONE 7(12): e49691. doi:10.1371/journal.pone.0049691 (Less)
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organization
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publication status
published
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in
PLoS ONE
volume
7
issue
12
publisher
Public Library of Science
external identifiers
  • wos:000312386800006
  • scopus:84871318806
ISSN
1932-6203
DOI
10.1371/journal.pone.0049691
language
English
LU publication?
yes
id
23a12328-3d44-4c10-bc27-227c09027b4c (old id 3366633)
date added to LUP
2013-02-01 08:57:16
date last changed
2017-01-01 05:33:39
@article{23a12328-3d44-4c10-bc27-227c09027b4c,
  abstract     = {Few studies have examined how foraging niche shift of a predator over time cascade down to local prey communities. Here we examine patterns of temporal foraging niche shifts of a generalist predator (yellow catfish, Pelteobagrus fulvidraco) and the abundance of prey communities in a subtropical lake. We predicted that the nature of these interactions would have implications for patterns in diet shifts and growth of the predator. Our results show significant decreases in planktivory and benthivory from late spring to summer and autumn, whereas piscivory increased significantly from mid-summer until late autumn and also increased steadily with predator body length. The temporal dynamics in predator/prey ratios indicate that the predation pressure on zooplankton and zoobenthos decreased when the predation pressure on the prey fish and shrimps was high. Yellow catfish adjusted their foraging strategies to temporal changes in food availability, which is in agreement with optimal foraging theory. Meanwhile the decrease in planktivory and benthivory of yellow catfish enabled primary consumers, such as zooplankton and benthic invertebrates, to develop under low grazing pressure via trophic cascading effects in the local food web. Thus, yellow catfish shifts its foraging niche to intermediate consumers in the food web to benefit the energetic demand on growth and reproduction during summer, which in turn indirectly facilitate the primary consumers. In complex food webs, trophic interactions are usually expected to reduce the strength and penetrance of trophic cascades. However, our study demonstrates strong associations between foraging niche of piscivorous fish and abundance of prey. This relationship appeared to be an important factor in producing top-down effects on both benthic and planktonic food webs. Citation: Xu J, Wen Z, Gong Z, Zhang M, Xie P, et al. (2012) Seasonal Trophic Niche Shift and Cascading Effect of a Generalist Predator Fish. PLoS ONE 7(12): e49691. doi:10.1371/journal.pone.0049691},
  author       = {Xu, Jun and Wen, Zhourui and Gong, Zhijun and Zhang, Min and Xie, Ping and Hansson, Lars-Anders},
  issn         = {1932-6203},
  language     = {eng},
  number       = {12},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {Seasonal Trophic Niche Shift and Cascading Effect of a Generalist Predator Fish},
  url          = {http://dx.doi.org/10.1371/journal.pone.0049691},
  volume       = {7},
  year         = {2012},
}