Data from: Differential effects of food availability on minimum and maximum rates of metabolism

Metabolic rates reflect the energetic cost of living but exhibit
remarkable variation among conspecifics, partly as a result of the
constraints imposed by environmental conditions. Metabolic rates are
sensitive to changes in temperature and oxygen availability, but effects
of food availability, particularly on maximum metabolic rates, are not
well understood. Here, we show in brown trout (Salmo trutta) that maximum
metabolic rates are immutable but minimum metabolic rates increase as a
positive function of food availability. As a result, aerobic scope (i.e.
the capacity to elevate metabolism above baseline requirements) declines
as food availability increases. These differential changes in metabolic
rates likely have important consequences for how organisms partition
available metabolic power to different functions under the constraints
imposed by food availability.

代谢速率（metabolic rate）反映了生物生存的能量消耗成本，但同种个体间的代谢速率存在显著差异，这在一定程度上源于环境条件施加的约束。代谢速率对温度与氧气供应的变化较为敏感，但食物供应的影响，尤其是对最大代谢速率的影响，目前尚未得到充分阐释。本研究以褐鳟（Salmo trutta）为研究对象，发现其最大代谢速率恒定不变，而最小代谢速率则随食物供应水平提升呈正相关增长。由此，有氧代谢范围（aerobic scope，即代谢速率提升至基线需求以上的能力）随食物供应水平提升而降低。代谢速率的这类差异性变化，可能对生物在食物供应施加的约束条件下，如何将可获取的代谢能量分配至不同生理功能具有重要影响。