The lateral line system of fishes is composed of neuromast mechanoreceptors that detect movement through vibration and changes in pressure gradients in the water. Although mechanosensory information has been shown to be important in the contexts of predator escape and foraging, little is known about the role of the lateral line system during intraspecific interactions, such as reproduction. However, many species of fish demonstrate complex courtship and aggressive repertoires that involve movement of the body and fins, resulting in local displacement of the surrounding water. This displacement has the potential to function as a signal that contains information about the sender. In this study, we conducted two behavioural experiments using fathead minnows, Pimephales promelas, to test the hypothesis that the outcomes of male–male contests and male–female courtship interactions are influenced by hydrodynamic flows generated during conspecific interactions. In the first experiment, we pitted control males against those with an ablated lateral line system and assessed both overall aggression and the likelihood of territory acquisition. In the second experiment, we conducted dual-choice female mate choice experiments to determine whether control females and those without access to mechanosensory information (ablated females) differed in patterns of discrimination and the use of courtship as a criterion of choice. In experiment 1, control males won a significantly greater proportion of territorial contests than expected by chance and were more likely to use noncontact threat displays during aggressive interactions compared with ablated males. In experiment 2, females with access to the mechanosensory information channel showed enhanced mate discrimination compared to ablated females. These data are among the first to show that mechanosensory signals are an important criterion of territorial and reproductive success in fishes and are likely important contributors to multimodal communication in this group.

中文翻译：

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身体产生的水动力流动影响淡水鱼的雄性竞争和雌性择偶

鱼类的侧线系统由神经柱机械感受器组成，通过振动和水中压力梯度的变化来检测运动。尽管机械感应信息已被证明在捕食者逃逸和觅食的背景下很重要，但对侧线系统在种内相互作用（如繁殖）中的作用知之甚少。然而，许多种类的鱼表现出复杂的求偶行为和侵略性的行为，包括身体和鳍的运动，导致周围水域的局部位移。这种位移有可能充当包含有关发送者信息的信号。在这项研究中，我们使用黑头鲦鱼、Pimephales promelas、检验男性-男性竞争和男性-女性求爱互动的结果受同种互动期间产生的流体动力学影响的假设。在第一个实验中，我们将对照雄性与侧线系统消融的雄性进行了对比，并评估了整体攻击性和获得领土的可能性。在第二个实验中，我们进行了双重选择雌性择偶实验，以确定对照雌性和那些无法获得机械感觉信息的雌性（消融雌性）在歧视模式和使用求爱作为选择标准方面是否存在差异。在实验 1 中，控制男性赢得的领土竞赛的比例明显高于偶然预期，并且与消融男性相比，更有可能在攻击性互动期间使用非接触式威胁展示。在实验 2 中，与被切除的雌性相比，可以访问机械感觉信息通道的雌性表现出更强的配偶歧视。这些数据首先表明机械感应信号是鱼类领土和繁殖成功的重要标准，并且可能是该群体中多模态交流的重要贡献者。