Trophic fingerprint of fish communities in subtropical floodplain lakes |
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| Authors: | Huan Zhang Huan Zhang Gongguo Wu Peiyu Zhang Jun Xu |
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| Institution: | 1. Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology of China, Institute of Hydrobiology, Chinese Academy of Sciences, , Wuhan, 430072 P. R. China;2. Graduate School of the Chinese Academy of Sciences, , Beijing, 100080 P. R. China;3. Fisheries College, Huazhong Agricultural University, , Wuhan, 430072 P. R. China |
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| Abstract: | Stable nitrogen isotope ratios (δ15N) and gut content analysis are commonly used to detect trophic relationships in aquatic systems. Nonetheless, the use of δ15N in determining the suitability of quantitative and qualitative dietary data as representations of trophic relationships in lake ecosystems remains unverified. Quantitative and qualitative dietary data on 46 fish species were obtained from field surveys in the floodplain lakes of the Yangtze Plain to calculate trophic position and benthivory. Dietary measures using the stable isotope approach were validated. The dietary approach yields comparable results in detecting trophic relationships in lake ecosystems. Our estimation of the benthivory of the 46 fish species ranged from 1.5% to 100%, with an average of 60.3%. These figures support the assumption that benthic energy pathways account for more than half of total fish consumption. Our feeding guild data confirm that more than 50% (including 25 species) of the studied fish species in the floodplain lakes of the Yangtze Plain are omnivorous, suggesting that omnivory is prevalent among subtropical floodplain lakes. |
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| Keywords: | trophic position stable isotope dietary fish benthic omnivory habitat coupling feeding guild trophic relationship |
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