Mechanisms of increasing predation by planktivorous fish with rising temperature may explain the temperature–body size relationships in zooplankton

The temperature–size rule (TSR) has been consistently observed in numerous studies, showing that ectotherms reared at higher temperatures experience accelerated growth during the juvenile stage and ultimately reach smaller sizes younger ages maturity. One explanation for this response is it occurs when effect of temperature on mortality, including predation, outweighs its food intake metabolism. While several studies have found latter close to expected result based Q 10 = 2 assumption, confirmation hypothesis requires evidence mortality exceeds threshold. To test hypothesis, we conducted experiments with two fish species: rudd Malabar danio. We examined capture rate, which serves as a proxy well standard metabolic rate (SMR) parameters characterising mobility their planktonic prey ( Daphnia ) different temperatures. results strongly supported our increased significantly more than especially This substantial cannot be attributed solely thermal sensitivity SMR, SMR was only around 2. most likely seems much pronounced increase fish’s resulting reaction field volume compared elevated leads an improved attack by fish, prediction made assumption. mechanism may explain not TSR pattern zooplankton, but also reduced mean body size density population community levels temperatures, hypothetically other predator–prey interfaces.