Abstract Objectives: Copepods display distinct feeding modes to capture prey in the surrounding water. However, the mechanism and range of prey detection are not fully understood. Methods: Using the method of regularized Stokeslets, we constructed a mathematical model of the flow field around a copepod engaged in three modes of movement: sinking, swimming and hovering. The model assumes that the copepod is negatively buoyant with a simplified body and a pair of long antennae. We then introduced a rigid, neutrally buoyant sphere in the model to predict where potential prey items become detectable in theory. Key Findings: We find that the flow fields around the sinking and swimming models are generally unidirectional, while the flow around a hovering copepod has a significant cross-stream component. Our model shows that the volume of the surrounding fluid that is predicted to be inspected has distinctive shapes that resemble a thin sheet while sinking, a cylinder while swimming and a funnel while hovering. Conclusion: The results suggest that the most efficient mode of feeding depends on the distribution of prey items in the surrounding water.
Read full abstract