Abstract

Small planktonic organisms live a difficult life in open waters, having to continuously scan large amounts of water for food and mates, and hide from predators at the same time. In the absence of vision at these small scales, chemical and mechanical cues are highly important, creating an evolutionary pressure to minimize any disturbances generated during feeding and locomotion. In this talk, I will present our examination of these processes using a combination of experiments and theory. We have measured flow disturbances created during swimming of a wide range of zooplankton, and found that the decay of hydrodynamic disturbance relates to the swimming mode. Breast stroke, a common swimming mode in plankton, results in “quiet” swimming, in which flow velocity decays with distance cubed. We used a simple three point force model to simulate this swimming gait, the results from which agree well with experiments. Finally, I will show some ongoing work in which we combine the model and experiments to assess the hydrodynamic traits of breast stroke swimming plankton.