Collaborative Research: Behavioral and neural mechanisms for predator evasion in crustacean zooplankton

在这个项目中，研究人员将研究海洋甲壳类桡足类动物捕食者逃避行为的个体发育。捕食者-猎物相互作用的神经行为学机制是浮游物种在所有发育阶段取得成功的基础。这种方法将是跨学科的，整合了行为、形态和神经生理学研究。具体目标是：a)记录从无节幼体到成年的不同生命阶段逃逸反应的发展，并将变化的逃逸行为与感觉、运动和中枢神经系统的发育联系起来；b)描述不同生活阶段环境条件对逃逸的影响；以及c)表征对自然捕食者的逃逸行为的发展。捕食往往是浮游生物死亡的最大来源。不同的海洋类群以不同的方式迎接了这一挑战。在甲虫类的桡足类动物中，它导致了很少有其他生物能与之匹敌的逃逸表现。这种表现的基础是一系列不寻常的神经运动特征，包括高机械感受性，高神经元放电频率能力，以及大约一半的Calanoid中出现有髓神经系统。在行为上，它包括对机械刺激的快速反应，肌肉能量的高输出和肌肉动作的高周期频率。传统的甲壳动物的生理特性不能解释桡足类的逃逸能力。这些动物如何取得显著的行为和生理表现，以及这些表现如何从无节幼体发展到成年，是理解它们成功的关键问题。由于金枪鱼对逃逸的投入如此之大，这些问题的答案与所有生物体中神经运动系统在生态和进化适应中所扮演的角色这一普遍问题密切相关。一种综合方法可以阐明这一点。专注于发展阶段将实现几个目标。对于许多动物群体来说，年轻个体(桡足类中的无节幼体和桡足类)的总体捕食风险高于成年个体。关于这种易感性的研究，特别是作为神经行为学问题的研究，相对较少。这项拟议的工作将制定出桡足类动物的发展战略，以提高其成熟后的行为能力。其次，通过研究比较发育阶段与成人的形态和生理特征，将有助于我们确定神经运动系统在发育过程中如何以及何时出现不同方面，以及这些方面与逃避能力之间的关系。最后，它将使科学界更好地了解捕食者-猎物在年轻阶段的相互作用。更广泛的影响包括培训研究生和本科生，以及为普通公众和K-12提供学习机会。该项目将支持对两名海洋科学研究生的培训，他们将在神经生理学、形态学和行为测试领域接受交叉培训。在K-12和社区层面，我们会制作一段短片，介绍浮游生物群落的生物相互作用，并继续发展和维持一个有关浮游动物感觉生态学的网站。

In this project the Investigators will examine the ontogeny of predator-evasion behavior in marine calanoid copepods. Neuroethological mechanisms underlying predator-prey interactions are fundamental to the success of planktonic species at all developmental stages. The approach will be interdisciplinary, integrating behavioral, morphological and neurophysiological studies. The specific objectives are: a) to document the development of the escape response in different life stages, from nauplius to adult, and correlate changing escape performance with the development of the sensory, motor and central nervous systems; b) to characterize the effect of variable environmental conditions on the escape of the different life stages; and c) to characterize the development of escape behavior to natural predators. Predation is often the greatest source of mortality for planktonic organisms. Different marine taxa have met this challenge in different ways. In calanoid copepods, it has led to an escape performance matched by few other organisms. Underlying this performance is an array of unusual neuromotor characteristics evolved in response to the predation pressure, including high mechanoreceptive sensitivity, high neuronal firing-frequency capabilities and the occurrence of myelinated nervous systems in about half of all calanoids. Behaviorally it includes fast reactions to mechanical stimuli, high output of muscle energy and high cycle rates of muscle action. Conventional crustacean physiological properties cannot account for copepod escape capabilities. How these animals achieve their remarkable behavioral and physiological performance and how the performance develops from nauplius to adult, are key questions in understanding their success. Because calanoids invest so heavily in escape, the answer to these questions relates strongly to the general issue in all organisms of the role played by the neuromotor system in ecological and evolutionary adaptations. An integrated approach can shed light on this. Focus on the developmental stages will achieve several goals. As for many animal groups, overall predation risk for younger individuals (nauplii and copepodites in copepods) is higher than for adults. Studies of this susceptibility, especially as a neuroethological issue, are relatively few. The proposed work will map out the copepod's developmental strategy for increasing behavioral competence as it matures. Secondly, through studies comparing morphological and physiological features of developmental stages with those in adults, it will help us determine how and when different aspects of the neuromotor systems appear during development and how these correlate with escape performance. Finally, it will give the scientific community a much better understanding of predator-prey interactions in the younger stages. Broader impacts include training of graduate and undergraduate students, as well as providing learning opportunities for the general public and K-12. The project will support the training of two graduate students in marine science, who will be cross-trained in areas of neurophysiology, morphology and behavioral testing. At the level of K-12 and the community we will develop a short video on biological interactions in plankton communities for public presentation and continue to develop and maintain a website on zooplankton sensory ecology