Flexibility in metabolic rate confers a growth advantage under changing food availability.
Flexibility in metabolic rate confers a growth advantage under changing food availability.
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DOI：
10.1111/1365-2656.12384
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发表时间：
2015-09
期刊：
影响因子：
--
通讯作者：
Metcalfe NB
中科院分区：
文献类型：
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作者：
Auer SK;Salin K;Rudolf AM;Anderson GJ;Metcalfe NB
生理、形态和行为特征的表型灵活性可以使生物体应对环境挑战。鉴于最近的气候变化和许多生物目前经历的栖息地改变程度，因此量化种群内存在的表型变异程度、个体变化能力及其对适应性的影响是至关重要的。标准代谢率（SMR）的灵活性可能特别重要，因为SMR反映了最小的能量生活成本，是生物体性能的主要特征之一。SMR会随着食物供应而增加或减少，但这些变化对生长速率和其他健康成分的影响尚不清楚。我们研究了褐鳟幼鱼代谢灵活性随食物水平变化的个体差异及其对体细胞生长的影响（Salmo trutta）。当个体切换到高食物配给时，SMR增加，当他们切换到低食物配给时，SMR减少。SMR的这些变化反过来又与体细胞生长的个体差异有关；那些在高食物水平下增加SMR的个体生长得最快，而那些在低食物水平下最抑制SMR的个体生长得最快。因此，能量代谢的灵活性是在食物供应可变性带来的挑战下实现生长速率最大化的关键机制，并且可能是物种面对全球变化时恢复力的重要决定因素。
Phenotypic flexibility in physiological, morphological and behavioural traits can allow organisms to cope with environmental challenges. Given recent climate change and the degree of habitat modification currently experienced by many organisms, it is therefore critical to quantify the degree of phenotypic variation present within populations, individual capacities to change and what their consequences are for fitness. Flexibility in standard metabolic rate (SMR) may be particularly important since SMR reflects the minimal energetic cost of living and is one of the primary traits underlying organismal performance. SMR can increase or decrease in response to food availability, but the consequences of these changes for growth rates and other fitness components are not well known. We examined individual variation in metabolic flexibility in response to changing food levels and its consequences for somatic growth in juvenile brown trout (Salmo trutta). SMR increased when individuals were switched to a high food ration and decreased when they were switched to a low food regime. These shifts in SMR, in turn, were linked with individual differences in somatic growth; those individuals that increased their SMR more in response to elevated food levels grew fastest, while growth at the low food level was fastest in those individuals that depressed their SMR most. Flexibility in energy metabolism is therefore a key mechanism to maximize growth rates under the challenges imposed by variability in food availability and is likely to be an important determinant of species’ resilience in the face of global change.