Meeting Abstract
Many fish exhibit (positive) rheotaxis, a behavior in which fish orient upstream with respect to the flow. Rheotaxis may confer many potential benefits, including energetic cost savings and improved interception of downstream drifting prey. Despite the fact that many species school during at least some portion of their life, little is known about the importance of rheotactic behavior to schooling fish and how the presence of nearby conspecifics affects rheotactic behavior. Understanding how these behaviors are modified by social factors is thus of ecological importance. Here we present an all-to-all consensus framework over the space (the N-torus) of fish headings to model group rheotactic behavior in which individuals receive noisy information about the relative headings of their neighbors and the flow direction – in inverse proportion to the flow speed. Using tools from control theory, we study the effect of flow speed and group size on rheotactic performance and generate testable predictions of fish behavior. The anticipated contributions of this work are (1) the extension of an existing consensus model to include a reference direction and unbounded (Von mises) noise; (2) the comparison of a biological metric of consensus with one used in control theory; and (3) investigation of the influence of noise values, the number of agents and flow speed one achieving consensus to a reference (upstream) direction. In ongoing work, we are conducting laboratory experiments to test the effect of social information on rheotactic behavior. The results of this study may have implications for fish ecology, collective behavior and flow sensing.
