Behavioral Cues Responsible for the Initiation and Maintenance of Copepod Swarms

本项目将通过计算机运动分析来研究个体和群体对光强度和信息素的反应，研究启动和维持海洋桡足动物群体行为的潜在线索。提出了蜂群行为模式的概念模型：暗光周期提供释放线索，阈值光强度提供唤醒线索，光强度梯度引起蜂群反应。个体在群体中定位的线索可能是光强度和/或信息素。这项研究将首先通过趋光性来确定光敏性，并通过记录个体游泳轨迹来确定对化学信息素信号的反应。在实验光梯度、光强变化和群体标记（光束）的存在下，将对实验室群体的游泳行为和个体在群体中的空间分布进行量化。将对实验室蝗群的生活史阶段组成进行操作，以测试来自成年雌性和其他蝗群阶段的信息素的影响。实验室的蜂群行为将与野外的蜂群行为进行比较。最初，所有的实验都将在中午进行，直到确定昼夜节律的存在与否。该研究将有助于验证群体行为的概念模型，为解释浮游动物聚集的原位观测提供框架，并提供可以包含在数学模型中的解释群体的机制。

This project will examine the potential cues that initiate and maintain swarm behavior in the marine copepod, Dioithona oculata, by computerized motion analysis to study individual and swarm responses to light intensity and pheromones. A conceptual model is presented for the swarming behavior pattern: diel light cycles provide a releasor cue, a threshold light intensity provides an arousal cue, and gradients of light intensity elicit a swarming response. Cues for individuals to orient in the swarm may be light intensity, and/ or pheromones. The study will first determine photosensitivity by phototaxis, and response to chemical pheromone signals by recording individual swimming tracks. The swimming behavior and spatial distribution of individuals in a swarm will be quantified for laboratory swarms in experimental light gradients, changes in light intensity, and presence of a swarm marker (beam of light). The life history stage composition of laboratory swarms will be manipulated to test for the effect of pheromones from adult females and other swarming stages. Laboratory swarm behavior will be compared to that of field swarms. Initially all experiments will be conducted during midday until the presence or absence of circadian rhythms has been determined. This study will help verify the conceptual model of swarm behavior, provide a framework for interpreting in situ observations of zooplankton aggregation, and provide mechanisms for explaining swarming which can be included in mathematical models.