Meeting Abstract
Flow is a major factor for life in water, affecting multiple fitness-determining functions such as reproduction, mass transfer, and the rate of encounter with prey and predator. While many fish species depend on the flow of water to carry the prey towards them, little is known on the mechanistic effect of water flow on the interaction between the prey and the predator. In this study, we used a recirculating flume to expose a station-keeping fish predator, Chromis viridis, to increasing approach speeds of their prey, Mysid shrimps. We tested the hypothesis that faster flows will reduce the response time of the prey, leading to increased capture success with increasing flow speed. Our results supported the hypothesis, with a doubling in the frequency of unsuccessful prey escape responses at fast flows (0.25 m/s) compared to slower speeds (<0.1 m/s). The increasing failure frequency was attributed to a delayed initiation of the prey’s escape response in high flow speeds. Lastly, we tested whether the prey responds to the predator’s kinematics by correlating the PC scores of predators’ strikes and those of prey escape. However, there was no significant correlation between the two factors. Our results show that water flow can have a strong mechanistic effect on predator-prey interactions.
