Multielement stoichiometry in aquatic invertebrates: when growth dilution matters

Element concentrations in organisms can be variable, often causing deviations from otherwise consistent, taxon-specific multielement stoichiometries. Such variation can have considerable ecological consequences, yet physiological mechanisms remain unclear. We tested the influence of somatic growth dilution (SGD) on multiple element concentrations under different bioenergetic conditions. SGD occurs when rapid individual growth causes a disproportional gain in biomass relative to gain of a specific element. SGD can strongly affect elements in various organisms, but we lack a general framework to unify results across studies and assess its overall importance. We derived the general conditions that trigger SGD from an element accumulation model. We parameterized the model with bioenergetic and element-specific rates summarized from the literature to compare SGD effects on 15 elements (nonessential metals, essential trace elements, macronutrients) in three aquatic invertebrate taxa. For all ...

生物体内的元素浓度存在波动，此类波动往往会偏离原本稳定的类群特异性多元素化学计量比。此类变异可产生显著的生态学效应，但其背后的生理机制仍未明确。我们在不同生物能学条件下，探究了个体生长稀释（somatic growth dilution, SGD）对多种元素浓度的影响。当个体快速生长导致生物量相较于特定元素的摄取量不成比例增加时，便会发生个体生长稀释效应。个体生长稀释可对多种生物内的各类元素产生显著影响，但目前尚无通用框架以整合不同研究的结果并评估其整体重要性。我们通过元素积累模型推导了触发个体生长稀释效应的通用条件。我们基于文献汇总的生物能学参数与元素特异性速率对模型进行参数化，以对比三种水生无脊椎动物类群中15种元素（非必需金属、必需微量元素、大量营养素）受个体生长稀释效应的影响情况。针对所有……