The biomechanics and energetics of locomotion in sea turtles: understanding the influence of load carrying on performance

海龟拥有脊椎动物最独特的身体结构(1)。海龟出现在2.2亿多年前的化石记录中。海龟在脊椎动物中是独一无二的，因为它们的整个身体都被包裹在一个坚硬的骨壳里，由甲壳和胎盘组成，以保护自己免受捕食者的侵袭。它们的壳似乎限制了它们的生活；然而，海龟生活在一系列水生和陆地栖息地，许多物种有效地在两者之间移动(2，3)。我们将结合生物学、生物力学和生理学技术，整理三种海龟的能量数据，从生物体到细胞水平(4)。我们选择了海龟，因为它们对不同负荷的专门化程度不同(5)，以提供广泛的范围，使我们能够更好地了解海龟的运动性能，不断变化的环境中的权衡，以及限制它们在箱中生活的影响。对海龟的研究将为未来功能多样性、适应和进化的研究提供重要的模型。水和空气是生物体必须在其中生存和运动的流体介质，这些环境之间的物理差异(密度、粘度、重力负荷)可能对海龟等经常横跨水生和陆地环境的生物体的适应和表现产生重要影响。这些陆地生物群在底物上也有关键的区别。我们将在生物体水平上确定负重如何影响运输和运动生物力学代谢成本的差异，并使用肌肉骨骼计算模型研究在环境变化的背景下最终在生理上限制海龟运动能力的适应。

Turtles have the most distinctive body plans of vertebrates (1). Turtles appear in the fossil record over 220 million years ago. Turtles are unique among vertebrates in that their whole body is enclosed within a rigid bony shell, composed of the carapace and plastron, that protects from predators. Their shells would appear to constrain their lives; however, turtles inhabit a range of both aquatic and terrestrial habitats and many species effectively move between both (2,3). We will integrate biological, biomechanical and physiological techniques to collate energetics data across three turtle species at the organismal down to the cellular level (4). We have selected sea turtles as they vary in their degree of specialisation to different loads(5) to provide a broad range that will allow us to better understand turtle locomotor performance, the trade-offs in changing environments and the impact of constraints on their life in a box. Studying turtles will provide an important model for future research on functional diversity, adaptation and evolution. Water and air represent the fluid media in which organism must survive and move and the physical disparities (density, viscosity, gravitational load) between these environments can have important consequences for adaptation and performance of organisms like turtles that routinely transverse between aquatic and terrestrial environments. There are key differences in substrate between these terrestrial biomes as well. We will determine how load bearing influences differences in the metabolic cost of transport and locomotor biomechanics at the organismal level and investigate using musculoskeletal computational models the adaptations that ultimately physiologically constrain locomotor performance in sea turtles in the context of environmental change.