Collaborative: IOS Full Proposal: RUI: Biting hard with soft feeding apparatuses

许多鱼通过用下颚剪掉肉块来进食，并经常用它们坚硬的身体骨骼产生运动来移除肉块。人们知之甚少的盲鳗也能有效地完成这项任务，尽管没有颌甚至没有脊柱。鹰目鱼依靠复杂的软肌肉和结缔组织来协调有力和动态的运动：1)独特的齿板，可以剪切大块食物；2)灵活的身体，松散的皮肤可以打结。身体结被压在胴体表面，这样盲鳗就可以获得杠杆作用来支持齿板的功能。本研究试图描述与使用软组织机制产生力和精确运动相关的功能原理。此外，本研究将为四名本科生和一名理学硕士学生提供培训，并开展国内和国际合作。pi和他们的学生将与三个当地的公共水族馆合作，开发展示盲鳗独特生物力学和行为的展览。最后，盲鳗的身体模型和模拟可能会导致实际应用的发展，例如具有动态打结能力的安全绳和可变形材料机制的生物灵感。本项目包括三部分分析。首先，牙板运动的生物力学分析将从基于解剖和三维x射线成像的形态学分析开始。由此产生的力是如何产生和传递的假设将通过分析喂食期间的高速视频和肌肉活动记录进行测试。其次，松散盲鳗皮肤的形态和材料特性可能对体结手法非常重要。皮肤形态将使用组织学重建来描述，材料性能将使用双轴拉伸试验来测量。然后，这些数据可以作为盲鳗体的简化模型的输入，该模型基于鞘/芯设计的柔性绳模型，在此基础上模拟结的形成和滑移。第三，为了评估体结行为对盲鳗“咬”强度的贡献，一个定制的水下力平台将记录剪切力和体结反作用力的大小和方向，食物将被拴在上面。这些研究的结果将通过在同行评议的期刊和科学会议上发表来传播。

Many fish feed by using their jaws to scissor away pieces of flesh and often generate movements with their rigid body skeletons to remove the piece. The poorly understood hagfish can also effectively accomplish this task despite lacking jaws or even a spine. Hagfish rely on complex arrangements of soft muscle and connective tissues to coordinate forceful and dynamic movements of 1) a unique toothplate that can shear off large chunks of food, and 2) flexible bodies with loose skins that can be tied into knots. Body knots are pressed against the surface of the carcass so that hagfish can gain leverage to support toothplate function. This study attempts to describe principles of function associated with generation of force and precision movements using soft tissue mechanisms. In addition, this research will provide training for four undergraduates and one Master of Science student and initiate national and international collaborations. The PIs and their students will work with three local public aquaria to develop exhibits that showcase unique hagfish biomechanics and behaviors. Finally, hagfish body models and simulations may result in the development of practical applications, such as safety ropes with dynamic knotting capabilities and bio-inspiration for deformable material mechanisms.This project encompasses a three-part analysis. First, the biomechanical analysis of toothplate movement will begin with a morphological analysis based on dissections and two- & three-dimensional X-ray imaging. Resulting postulates of how forces are produced and transmitted will be tested using analyses of high-speed video and muscle activity recordings during feeding bouts. Second, the morphology and material properties of the loose hagfish skin are likely very important to body knot manipulations. Skin morphology will be described using histological reconstructions and material properties will be measured using biaxial tensile tests. These data may then be used as input into a simplified model of the hagfish body, based on a flexible rope model of a sheath/core design, upon which to simulate knot formation and slippage. Third, in order to assess the contribution of body knotting behavior to hagfish 'bite' strength, a custom underwater force platform, to which food will be tethered, will record the magnitude and direction of shearing and body knot reaction forces. Results from the studies will be disseminated through publication in peer-reviewed journals and at scientific meetings.