Directional control in sea star locomotion with respect to light

Sea stars control hundreds of tube feet to navigate their environment with a rudimentary nervous system. Tube feet are capable of responding to stimuli without descending nervous commands and it is therefore unclear to what extent tactic orientation emerges through the collective action of the feet or is guided by central control. We therefore performed behavioral experiments to test models of neuromechanical control in a sea star (Protoreaster nodosus). We found that animals moved rapidly along relatively straight trajectories when exposed to light, but slowly crawled along circuitous paths in random directions in the dark. To remove mechanical interactions with the substrate, we measured the kinematics of tube feet in inverted sea stars that exhibited crawling when in contact with the water’s surface. The tube feet throughout the body of these animals moved with power strokes in a similar direction when the animals were exposed to light, which i..., The study investigated directional control in the tube feet of sea stars (Protoreaster nodosus) through experimental manipulation. Specifically, it examined the coordination of tube feet in response to light, both with and without mechanical coupling. The effects of directional stimuli were analyzed using kinematic assessments of individual sea stars. This repository contains the data, MATLAB, and R scripts used for all analyses in the study., , # Directional control in sea star locomotion with respect to light

DryAd DOI link: [https://doi.org/10.5061/dryad.b2rbnzsr9](https://doi.org/10.5061/dryad.b2rbnzsr9)

It remains unclear how hundreds of tube feet on sea stars coordinate their movements without a brain. Our research article investigates the behavior of Protoreaster nodosus—specifically, how its tube feet coordinate under different conditions. Previous evidence suggests that tube feet may coordinate through mechanical coupling with the body and substrate, although it is also possible that motor commands from the nervous system drive their coordination.

To test these possibilities, we designed an experiment to minimize mechanical coupling. We inverted the sea stars while providing a directional light stimulus. If the tube feet can still coordinate effectively in the inverted position, it would support the hypothesis that directional coordination is primarily a result of nervous system control rather than mechanical coupl...

海星依靠其原始神经系统操控数百只管足（tube feet）以感知周遭环境。管足无需中枢神经指令即可响应刺激，因此目前尚不明确，趋向定向行为究竟是管足集体运动的产物，还是受中枢调控主导。为此，我们针对花斑拟手尾海星（Protoreaster nodosus）开展行为实验，以验证其神经机械控制模型。研究发现，当暴露于光照环境时，海星可沿相对笔直的轨迹快速移动；而在黑暗环境中，则会沿迂回路径缓慢随机爬行。为排除与基底的机械相互作用干扰，我们对倒置海星的管足运动学进行了测量——这类海星在与水面接触时仍可完成爬行。当海星受光照刺激时，其全身各处的管足均会沿同一方向完成动力冲程，该研究……

本研究通过实验操控手段，探究了海星管足的定向控制机制，重点考察了管足在有无机械耦合条件下对光照的协调响应模式，并通过对单只海星的运动学分析，量化了定向刺激产生的影响。本数据集仓库包含本研究所有分析所需的数据、MATLAB及R脚本。

# 海星基于光照的运动定向控制

DryAd DOI链接：https://doi.org/10.5061/dryad.b2rbnzsr9

目前学界仍未明确，海星身上的数百只管足在无大脑调控的情况下如何协调运动。本研究论文聚焦于花斑拟手尾海星（Protoreaster nodosus）的行为模式，具体探究了其管足在不同环境条件下的协调机制。此前已有研究表明，管足或可通过与躯体及基底的机械耦合实现协调，但也有假说认为，神经系统发出的运动指令才是协调行为的驱动因素。

为验证上述两种假说，我们设计实验以最小化机械耦合的影响：将海星倒置，并施加定向光照刺激。若倒置状态下管足仍可实现有效协调，则可支持"定向协调主要由神经系统调控，而非机械耦合"这一假说……