Body size-mediated starvation resistance in an insect predator
Body size-mediated starvation resistance in an insect predator
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DOI：
10.1111/1365-2656.12195
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发表时间：
2014-07-01
影响因子：
4.8
通讯作者：
Jager, Tjalling
中科院分区：
文献类型：
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作者：
Gergs, Andre;Jager, Tjalling
生物个体必须忍受短暂的食物供应不足，这对生长、繁殖和生存造成了影响。为了抵抗饥饿，动物通常会在体内储存资源：动物越大，它们可以携带的资源就越多，但它们需要分配更多的能量来维持身体功能。目前还不清楚当食物稀缺或缺乏时，生存与体型的关系，以及如何描述种群中生存的个体差异。我们使用一个动态能量预算（DEB）模型来描述食物收购，随后的储备动态和分配储备的身体维持，生长和成熟的水生昆虫捕食者，Notonecta maculata。在DEB背景下，我们可以假设当生物体的储备耗尽到一定程度时，饥饿引起的死亡就会发生。储备动力学在饥饿时的变化方式可能会影响在缺乏食物的情况下生存的能力。此外，饥饿种群中的个体不会在同一时间死亡，即使它们可能具有相同的体型和相似的生活史。为了描述饥饿抗性的个体差异，我们将来自DEB模型的储备动态与通用统一阈值生存模型（GUTS）联系起来。我们测试了两种不同的特殊情况下，在GUTS，个体耐受性（IT）和随机死亡（SD），和三种不同的饥饿选项，其适用性在身体大小相关的饥饿抗性的实验数据。DEB模型较好地再现了不同食物条件下斑节对虾幼鱼发育的实验室数据，并能很好地预测个体在长期饥饿过程中的体重损失。组合的IT模型和组合的SD模型都很好地拟合了包括饥饿在内的不同食物条件下的生存。然而，这两个模型作出不同的预测反复短暂饥饿时期下的生存。我们的研究结果表明，较大的N.maculata标本能够抵抗饥饿在更大程度上比较小的同种。DEB模型提供了一个机械的解释身体大小和饥饿抗性之间的正相关关系，并提供了可检验的假设可能偏离这一总的趋势。
Individual organisms have to endure transient periods of low-food supply with consequences for growth, reproduction and survival. To resist starvation, animals usually store resources in their bodies: the larger the animals are, the more resources they can carry, but the more energy they need to allocate for maintaining bodily functions. It is unclear how survival relates to body size when food is scarce or absent, and how to characterize individual differences in survival within a population. We use a dynamic energy budget (DEB) model to describe food acquisition, subsequent reserve dynamics and allocation of reserve to body maintenance, growth and maturation of an aquatic insect predator, Notonecta maculata. In a DEB context, we can assume that starvation-induced death strikes when the reserve of an organism is depleted to a certain extent. The way reserve dynamics change upon starvation might thereby influence the ability to survive in the absence of food. Moreover, individuals in a starved population do not die at the same time, even though they might be of the same body size with similar life histories. To describe individual differences in starvation resistance, we link the reserve dynamics derived from the DEB model to the general unified threshold model of survival (GUTS). We tested two different special cases within GUTS, individual tolerance (IT) and stochastic death (SD), and three different starvation options for their suitability in representing experimental data on body size-related starvation resistance. The DEB model reproduced laboratory data on the development of juvenile N.maculata under different food conditions well and closely predicted the weight loss of individuals during prolonged starvation. Both the combined IT-model and the combined SD-model closely fit survival for different food conditions including starvation. However, the two models make different predictions for survival under repeated transient starvation periods. Our results suggest that larger N.maculata specimens are able to resist starvation to a greater extent than smaller conspecifics. The DEB model provides a mechanistic explanation for the positive relationship between body size and starvation resistance, and offers testable hypotheses for possible deviations from this general trend.