Hypoxia impairs the digestive advantage of individual southern catfish (Silurus meridionalis) with high resting metabolic rates and postprandial metabolic responses |
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Authors: | Bo-Jian Chen Zhen-Dong Cao |
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Institution: | Laboratory of Evolutionary Physiology and Behavior, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, China |
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Abstract: | Empirical studies suggest that individuals with a high resting metabolic rate (RMR) are at an advantage under favourable conditions because they digest food rapidly and exhibit a greater growth potential. However, we hypothesised that high-RMR individuals have less energy available for digestion under hypoxia than they do under normoxia due to their relatively high maintenance cost. To test this hypothesis, we measured the RMR and postprandial metabolic responses of juvenile southern catfish, Silurus meridionalis, under normoxia and moderate hypoxia. The results provided the first evidence that (1) both the RMR and postprandial metabolic rate showed repeatability across different water O2] conditions and (2) the correlation between the RMR and postprandial metabolic traits differs with changes in environmental factors (water O2]). These findings suggested that the digestive advantage of individual southern catfish with a high RMR is impaired under hypoxia. |
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Keywords: | digestion hypoxia metabolism interindividual variation southern catfish Silurus meridionalis |
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