Collaborative Research: Hydrodynamic and Muscular Mechanical Investigation of Maneuverability in Cephalopods throughout Ontogeny

乌贼和墨鱼是令人印象深刻的游泳者，它们能够悬停，快速改变方向，甚至轻松地向前和向后游泳。它们的运动能力的关键是它们的脉冲射流，扑鳍和灵活的手臂之间的协调，但目前对这些单位如何在这些动物的一生中协同工作知之甚少，因为它们遇到了不同的物理环境，发展变化，并经历了不同的生态系统。这个项目的重点是了解鱿鱼和墨鱼在不同的发育阶段（从孵化到成年），从肌肉能力和流体动力学的角度来看，喷气、鳍和臂是如何协同工作的，以产生必要的力量来实现特殊的转弯。这项工作将涉及尖端的3D流可视化方法、高速视频分析和先进的数学工具，以突出高性能转弯的基本组成部分。该项目有望(1)推进我们对高机动性海洋动物如何在其复杂栖息地中导航的理解；(2)揭示关键的性能特征、结构和行为，这些特征、结构和行为可以潜在地集成到机械生物启发系统的设计中，例如自主水下航行器，以提高它们的转弯/停靠能力。该项目包含了许多扩展项目，包括在当地学校的演示，参与机器人竞赛，开发基于网络的教程和夏令营，以及在水族馆和博物馆的演示。在水生环境中，机动是日常游泳的重要组成部分，熟练的机动对于躲避捕食者、捕获猎物和导航至关重要。尽管它很重要，但对机动行为的生物力学的理解是有限的。本文对三种形态不同的头足类动物的机动性能进行了研究。该研究探讨了三个主要问题：(1)成年头足类动物的鳍、臂和漏斗射流是如何协同使用以最大限度地提高转弯性能的；(2)转弯速率和转弯半径对个体发育的影响相对重要，幼头足类的转弯模式较少；(3)鳍、臂和漏斗肌肉骨骼力学是否在个体发育过程中发生变化，这些变化是否与机动的差异有关？这些问题将通过收集尾流的三维高速运动学和二维/三维流体动力学的测量来解决；进行数学分析，定量识别和分类车削模式；测量动态被动和主动长度-力关系以及肌肉纤维的最大缩短速度，这些肌肉纤维在转弯和喷射矢量过程中驱动运动。提出的工作将：(1)提供关于生态上重要的海洋动物如何协调其新型双模系统（射流和鳍）和手臂以获得高转弯性能的数据；(2)突出转弯的基本运动学和流体动力学因素；(3)提供关于在广泛的个体发生范围内如何改变机动能力的见解；(4)提供关于肌肉流体静力器官的肌肉特性及其在转弯中的作用的新数据。

Squids and cuttlefishes are impressive swimmers, having the ability to hover, change direction rapidly, and even swim forward and backward with ease. The key to their locomotive prowess is coordination among their pulsed jet, flapping fins, and flexible arms, but little is presently known about how these units work together throughout these animals' lives as they encounter different physical environments, change developmentally, and experience dissimilar ecosystems. This project focuses on understanding how the jet, fins, and arms operate in concert to produce the necessary forces for exceptional turning, both in terms of muscle capabilities and hydrodynamics, in squid and cuttlefish of different developmental stages (hatchlings to adults). This work will involve cutting edge 3D flow visualization approaches, high-speed video analysis, and advanced mathematical tools that highlight the essential components of high-performance turns. This project promises to (1) advance our understanding of how highly maneuverable marine animals navigate through their complex habitats and (2) reveal key performance characteristics, structures, and behaviors that can be integrated potentially into the design of mechanical bio-inspired systems, such as autonomous underwater vehicles, to improve their turning/docking capabilities. This project incorporates a number of outreach projects, including demonstrations in local schools, participation in robotics competitions, development of web-based tutorials and summer camps, and presentations at aquariums and museums. Maneuvering in the aquatic environment is a significant component of routine swimming, with proficient maneuvering being essential for predator avoidance, prey capture, and navigation. Despite its importance, understanding of the biomechanics of maneuvering behaviors is limited. An investigation of maneuvering performance in three morphologically distinct species of cephalopods is proposed here. The investigation explores three broad questions: (1) how are the fins, arms, and funnel-jet complex used in concert to maximize turning performance in adult cephalopods; (2) do the relative importance of turning rate and turning radius change over ontogeny and are fewer turning modes observed in young cephalopods; and (3) do fin, arm, and funnel musculoskeletal mechanics change over ontogeny and are such changes associated with differences in maneuvering? These questions will be addressed by collecting measurements of 3D high-speed kinematics and 2D/3D hydrodynamics of wake flows; performing mathematical analyses to quantitatively identify and categorize turning patterns; and measuring both the dynamic passive and active length-force relationship and maximum shortening velocity of muscle fibers that drive the movements used during turning and jet vectoring. The proposed work will: (1) provide data on how an ecologically important marine animal coordinates its novel dual-mode system (jet and fins) and arms to achieve high turning performance, (2) highlight the essential kinematic and hydrodynamic elements of turns, (3) offer insights into how maneuvering capabilities change over a broad ontogenetic range, and (4) provide novel data on the muscle properties of muscular hydrostatic organs and their role in turning.