Brittle stars are known for the high flexibility of their arms, a characteristic required for locomotion, food grasping, and for holding onto a great diversity of substrates. Their high agility is facilitated by the numerous discrete skeletal elements (ossicles) running through the center of each arm and embedded in the skin. While much has been learned regarding the structural diversity of these ossicles, which are important characters for taxonomic purposes, their impact on the arms' range of motion, by contrast, is poorly understood. In the present study, we set out to investigate how ossicle morphology and skeletal organization affect the flexibility of brittle star arms. Here, we present the results of an in-depth analysis of three brittle star species (Ophioplocus esmarki, Ophiopteris papillosa, and Ophiothrix spiculata), chosen for their different ranges of motion, as well as spine size and orientation. Using an integrated approach that combines behavioral studies with parametric modeling, additive manufacturing, micro-computed tomography, scanning electron microscopy, and finite element simulations, we present a high-throughput workflow that provides a fundamental understanding of 3D structure-kinematic relationships in brittle star skeletal systems.

中文翻译：

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脆性星臂运动学的结构起源：一种集成的层析成像、增材制造和基于参数化建模的方法。

脆星以其手臂的高度柔韧性而闻名，这是运动、抓取食物和抓住各种基质所必需的特征。它们的高敏捷性得益于许多离散的骨骼元素（小骨），它们穿过每只手臂的中心并嵌入皮肤中。虽然对这些小骨的结构多样性已经了解很多，这些小骨是分类学上的重要特征，但相比之下，它们对手臂运动范围的影响却知之甚少。在本研究中，我们着手研究小骨形态和骨骼组织如何影响脆性星臂的柔韧性。在这里，我们展示了对三种脆性星种（Ophioplocus esmarki、Ophiopteris papillosa 和 Ophiothrix spiculata）的深入分析结果，选择不同的运动范围，以及脊柱的大小和方向。使用将行为研究与参数化建模、增材制造、显微计算机断层扫描、扫描电子显微镜和有限元模拟相结合的集成方法，我们提出了一种高通量工作流程，可从根本上了解脆性星的 3D 结构-运动学关系骨骼系统。