Physiological Responses to Predators and Their Consequences for the Growth/Predation Risk trade-off

许多生物通过改变它们的生理、行为和形态来应对捕食者的威胁。这些试图降低它们被捕食者杀死的可能性的努力，往往是以减少生长为代价的。尽管从细菌到植物和动物的生物体都表现出这种反应，但这种权衡的潜在原因却鲜为人知。在捕食者存在的情况下，生长减少可能部分是由于减少摄食的行为反应，但生理变化也可能起主要作用。本研究将探讨蜻蜓幼虫(六足纲：蜻蜓目)在对捕食者的生理反应上的差异，这些差异对代谢资源分配和行为的影响，以及这些特征的进化。将进行五项研究，以检查物种的生理反应以及摄取的资源对体内各种分子的分配。第一项研究将对12种生物进行调查，以测量生物体内的自然生长率以及葡萄糖、糖原、甘油三酯和蛋白质的含量。第二个实验将通过实验确定在实验室中捕食者的存在和食物可获得性的处理下这些分子的生长和分配的变化。第三个是现场实验，以检验在控制实验室实验中获得的结果是否在真实湖泊中得到证实。第四个测试是关于引起生理反应的属之间的近似差异的假设。最后，第五部分考察了这种对捕食者的生理反应的更广泛的进化史。这项工作探索了两类昆虫在生态表现上根本差异的生理机制。这对于理解一个人的表型如何塑造其与环境和其他物种相互作用的能力至关重要。此外，研究这种生理学是如何进化的，为物种如何适应各种环境以及自然和人类活动引起的环境变化(例如，自然栖息地变化、气候变化、栖息地退化)提供了宝贵的见解。

Many organisms respond to the threat of predators by altering their physiology, behavior and morphology. These attempts to reduce their likelihood of being killed by a predator, often come at the cost of reducing growth. Although organisms from bacteria to plants and animals show such responses, the underlying reasons for this trade-off are poorly understood. Reduced growth in the presence of predators may result in part from behavioral responses to reduce feeding, but physiological changes also may play a major role. This research will explore the differences among species and genera of larval damselflies (Hexapoda: Odonata) in physiological response to predators, the consequences of these differences for metabolic resource allocation and behavior, and the evolution of these traits. Five studies will be performed to examine the physiological responses of species and the allocation of ingested resources to various molecules in the body. The first study will survey 12 species to measure natural growth rates and the amount of glucose, glycogen, triglycerides and protein in the organism's body. The second will experimentally determine alterations in growth and allocation to these molecules under treatments of predator presence and food availability in the lab. The third is a field experiment to test whether the results obtained in the controlled laboratory experiment are substantiated in real lakes. The fourth tests hypotheses about the proximate differences between the genera that induce the physiological response. Finally, the fifth examines the broader evolutionary history of this physiological response to predators.This work explores the physiological mechanisms underlying a fundamental difference in ecological performance between two groups of insects. This is critical to understanding how an individual's phenotype shapes its ability to engage in interactions with its environment and with other species. Also, examining how this physiology has evolved provides valuable insights into how species adapt to various environments and to natural and anthropogenically-induced environmental change (e.g., natural habitat shifts, climate change, habitat degradation).