Decreased trophic position as a function of increa

Authors: Yuyu Wang Xiubo Yu Jun Xu

Publish Date: 2011/04/15

Volume: 91, Issue: 4, Pages: 505-512

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Abstract

Potential body sizetrophic position relationships of the Darkbarbel catfish Pelteobagrus vachelli Richardson 1846 were examined using stable isotope analysis Pelteobagrus vachelli is a benthic feeding fish from Lake Poyang the largest freshwater lake in China Twosource mixing model with mussel Corbicula fluminea and snail Bellamya aeruginosa as baseline primary consumers of planktonic and benthic food webs respectively was used to estimate contribution of carbon derived from planktonic vs benthic food web Results showed that as an indicator of trophic position δ15N was negatively correlated with the body length and weight of the fish on the other hand as an indicator of the endmember food sources δ13C was not correlated with fish size The mixing model results showed that the averaged trophic position of our sampled 33–127 cm Pelteobagrus vachelli was 31 ± 02 and derived 68 ± 27 of their food from the benthic food web confirming that the feeding behavior of the catfish favors benthic food sourcesWe would like to express our sincere thanks to Yuwei Chen Lu Zhang and the staff of Lake Poyang Laboratory for Wetland Ecosystem Research Nanjing Institute of Geography and Limnology Chinese Academy of Sciences for their help in field work and data collection in Lake Poyang Input from anonymous reviewers also helped improve this manuscript substantially This study was supported by the 973 Plan Grant No 2009CB421106 the National Science and Technology Support Plan Grant No 2006BAC08B05 and the National Natural Science Foundation of China Grant No 30870428 Funding was also awarded to JX by the K C Wong Education Foundation and the Knowledge Innovation Program of the Chinese Academy of Sciences

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