The combined effect of body size and temperature on oxygen consumption rates and the size‐dependency of preferred temperature in European perch Perca fluviatilis

Abstract

The present study determined the effect of body mass and acclimation temperature (15–28°C) on oxygen consumption rate (ṀO2) and the size dependency of preferred temperature in European perch Perca fluviatilis. Standard metabolic rate (SMR) scaled allometrically with body mass by an exponent of 0.86, and temperature influenced SMR with a Q10 of 1.9 regardless of size. Maximum metabolic rate (MMR) and aerobic scope (MMR‐SMR) scaled allometrically with body mass by exponents of 0.75–0.88. The mass scaling exponents of MMR and aerobic scope changed with temperature and were lowest at the highest temperature. Consequently, the optimal temperature for aerobic scope decreased with increasing body mass. Notably, fish <40 g did not show a decrease aerobic scope with increasing temperature. Factorial aerobic scope (MMR × SMR−1) generally decreased with increasing temperatures, was unaffected by size at the lower temperatures, and scaled negatively with body mass at the highest temperature. Similar to the optimal temperature for aerobic scope, preferred temperature declined with increasing body mass, unaffectedly by acclimation temperature. The present study indicates a limitation in the capacity for oxygen uptake in larger fish at high temperatures. A constraint in oxygen uptake at high temperature may restrict the growth of larger fish with environmental warming, at least if food availability is not limited. Furthermore, behavioural thermoregulation may be contributing to regional changes in the size distribution of fish in the wild caused by global warming as larger individuals will prefer colder water at higher latitudes and at larger depths than smaller conspecifics with increasing environmental temperatures.

Effects of global warming on fishes and fisheries

“…Christensen et al . (2020) investigated how metabolism is affected by temperature and body size in European perch Perca fluviatilis L. 1758. They provide evidence that larger animals may perform less well at warm temperatures, with potential implications for effects of warming on perch sizes and distribution.…”

Effects of temperature on physiological performance and behavioral thermoregulation in an invasive fish, the round goby

“…This theory assumes that the temperature preference of a species is determined by limitations in meeting organismal oxygen demands at high temperature, which restricts physiological performance and is aptly named the oxygen-and capacity-limited thermal tolerance (OCLTT) theory. Some empirical evidence supports the OCLTT theory (Reynolds and Casterlin, 1979;Jobling, 1981;Habary et al, 2016;Christensen et al, 2020) while other evidence does not (Clark et al, 2013;Jutfelt et al, 2018;Gräns et al, 2014;Norin et al 2014). For round goby, the preferred temperature (21.2°C) fell in the middle of the temperature range that enabled the fish to achieve a high aerobic scope (15-28°C), but was lower than the temperature where the fish achieved the numerically highest aerobic scope (28°C).…”

Paths towards greater consensus building in experimental biology

“…However, comparative physiologists have argued that there is sufficient evidence in the physiological literature to reject the GOL hypothesis (Lefevre et al, 2017). Subsequent papers have continued the discussion about the merits of the GOL hypothesis (Audzijonyte et al, 2019;Lefevre et al, 2018;Marshall and White, 2019;Pauly, 2021;Pauly and Cheung, 2018a,b), and researchers have since begun directly and indirectly testing the hypothesis using new experiments and previously collected data (Bigman et al, 2021;Christensen et al, 2020;Meyer and Schill, 2021;Scheuffele et al, 2021;Shapiro Goldberg et al, 2019).…”