Xeniid corals (Cnidaria: Alcyonacea), a family of soft corals, include species displaying a characteristic pulsing behavior. This behavior has been shown to increase oxygen diffusion away from the coral tissue, resulting in higher photosynthetic rates from mutualistic symbionts. Maintaining such a pulsing behavior comes at a high energetic cost, and it has been proposed that coordinating the pulse of individual polyps within a colony might enhance the efficiency of fluid transport. In this paper, we test whether patterns of collective pulsing emerge in coral colonies and investigate possible interactions between polyps within a colony. We video recorded different colonies of Heteroxenia sp. in a laboratory environment. Our methodology is based on the systematic integration of a computer vision algorithm (ISOMAP) and an information-theoretic approach (transfer entropy), offering a vantage point to assess coordination in collective pulsing. Perhaps surprisingly, we did not detect any form of collective pulsing behavior in the colonies. Using artificial data sets, however, we do demonstrate that our methodology is capable of detecting even weak information transfer. The lack of a coordination is consistent with previous work on many cnidarians where coordination between actively pulsing polyps and medusa has not been observed. In our companion paper, we show that there is no fluid dynamic benefit of coordinated pulsing, supporting this result. The lack of coordination coupled with no obvious fluid dynamic benefit to grouping suggests that there may be non-fluid mechanical advantages to forming colonies, such as predator avoidance and defense.

中文翻译：

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Xeniid 珊瑚中的集体脉冲：第 I 部分——使用计算机视觉和信息理论寻找协调

Xeniid 珊瑚（刺胞动物：Alcyonacea）是一个软珊瑚家族，包括表现出特征性脉动行为的物种。这种行为已被证明会增加氧气从珊瑚组织中的扩散，从而提高共生体的光合作用速率。维持这种脉动行为需要付出高昂的能量成本，并且有人提出协调菌落内单个息肉的脉动可能会提高液体运输的效率。在本文中，我们测试了珊瑚群中是否出现了集体脉冲模式，并调查了群落内息肉之间可能的相互作用。我们用视频记录了 Heteroxenia sp 的不同菌落。在实验室环境中。我们的方法基于计算机视觉算法 (ISOMAP) 和信息理论方法（传递熵）的系统集成，为评估集体脉冲中的协调提供了有利位置。也许令人惊讶的是，我们没有在殖民地发现任何形式的集体脉冲行为。然而，使用人工数据集，我们确实证明了我们的方法能够检测甚至微弱的信息传输。缺乏协调与以前对许多刺胞动物的工作一致，其中没有观察到主动脉动息肉和美杜莎之间的协调。在我们的配套论文中，我们表明协调脉冲没有流体动力学优势，支持这一结果。