Collaborative Research: Exploring the interplay between form and function: the force-velocity trade-off in the spider predatory strike.

蜘蛛是昆虫和其他小动物的重要捕食者，该群体有近50，000种描述。它们是最多样化和数量最多的动物群体之一，占据了各种各样的栖息地;蜘蛛在控制害虫种群方面也发挥着重要作用。虽然在了解蜘蛛如何使用丝和毒液来捕获猎物方面取得了很大的进展，但对蜘蛛的主要进食结构--螯肢却知之甚少。在某些方面，它们的功能类似于脊椎动物的颌骨，因为它们用于抓住和处理猎物。本研究的重点是在捕食攻击过程中，当蜘蛛抓住猎物并向其注射毒液时，螯肢是如何使用的，以及螯肢的形状、速度和力量在不同的蜘蛛群体中是如何变化的。研究人员将比较各种蜘蛛中螯肢的解剖和运动，以更好地了解群体中进食的进化。这项工作还将研究在某些类型的蜘蛛中发现的超快速捕食性攻击的细节，并确定它是如何进化的。除了揭示蜘蛛螯肢的功能和进化外，该项目还向下一代科学家介绍了蜘蛛生物学，并与从高中生到博士后学者的几个群体进行了外联。这项研究的结果也将被用来参与和教育公众，包括学龄儿童，通过动手的经验教训，将在国家自然历史博物馆展出，并在马里兰州大学的夏令营使用。这项研究的重点是比较功能形态的蜘蛛螯，并测试假设，一个基本的生物力学原理，力-速度权衡，解释了它们形态的多样性和捕食性罢工动态。人们普遍认为，基于神经网络的骨骼肌系统被优化以产生高的力或高的速度，但不能同时产生两者。力-速度假说的预测将使用蜘蛛生命树中广泛的物种样本进行测试，包括“陷阱-下巴”蜘蛛，其中一些具有捕食性攻击，这是蛛形纲动物中已知的最快运动。外骨骼和肌肉组织的结构细节将通过计算机断层扫描和组织学切片的分析进行量化，功能性能变量（如打击速度）将通过分析高速视频进行测量。将产生一个分子生物学，并用于提供历史框架，研究形态和罢工性能的演变。系统发育学的统计分析将用于确定力-速度权衡所预期的形式和功能之间的相关性是否与蜘蛛中观察到的生物力学多样性一致。这些结果将为骨骼肌系统的形式和功能的进化提供深入的见解，并为蜘蛛生物学提供丰富的新信息来源。该奖项由生物科学理事会的两个项目共同资助，即环境生物学部的系统学和生物多样性科学项目，以及综合有机体系统部的生理机制和生物力学项目。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Spiders are important predators of insects and other small animals, and the group has nearly 50,000 described species. They are one of the most diverse and numerous groups of animals and occupy a wide variety of habitats; spiders also play an essential role in controlling pest populations. While great advances have been made in understanding how spiders use silk and venom to capture prey, very little is known about the main feeding structures of spiders, the chelicerae. These in some respects function like jaws of vertebrates since they are used to grasp and process prey. This research focuses on how the chelicerae are used during the predatory strike, when the spider grasps the prey and injects it with venom, and how the shape, speed and strength of chelicerae vary in different groups of spiders. The researchers will compare the anatomy and movements of chelicerae in a wide variety of spiders to better understand the evolution of feeding in the group. This work will also examine details of the super-fast predatory strike, found in certain types of spiders, and determine how it evolved. In addition to revealing the function and evolution of spider chelicerae, the project introduces spider biology to the next generation of scientists, with outreach to several groups ranging from high-school students to postdoctoral scholars. Results from this research will also be used to engage and educate the public, including school-aged children, through hands-on lessons that will be displayed at the National Museum of Natural History and used in a summer day camp at the University of Maryland.This research focuses on the comparative functional morphology of spider chelicerae, and tests the hypothesis that a fundamental biomechanical principle, the force-velocity trade-off, explains the diversification of their morphology and predatory strike dynamics. It is widely assumed that lever-based skeletomuscular systems are optimized to produce either high forces or high velocities, but not both simultaneously. Predictions of the force-velocity hypothesis will be tested using a broad sample of species from across the spider tree of life, including the “trap-jaw” spiders, some of which have predatory strikes that are the fastest movements known among arachnids. Structural details of the exoskeleton and musculature will be quantified through analysis of Computed Tomography scans and histological sections, and functional performance variables such as strike velocity will be measured through analysis of high-speed videos. A molecular phylogeny will be generated and used to provide the historical framework for examining the evolution of morphology and strike performance. Phylogenetically-informed statistical analyses will be used to determine whether the correlations between form and function anticipated by the force-velocity trade-off are consistent with the biomechanical diversity observed in spiders. The results will offer insights into the evolution of form and function in skeletomuscular systems and provide a rich source of new information on spider biology. This award is co-funded by two programs in the Directorate for Biological Sciences, the Systematics and Biodiversity Science Program in the Division of Environmental Biology, and the Physiological Mechanisms and Biomechanics Program in the Division of Integrative Organismal Systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.