Abstract
Turbulence plays an important role for feeding process of planktonic organisms in aquatic environments. Small scale turbulence benefits the predator by increasing its encounter rate with prey, but makes the predator more difficult to capture the prey by reducing the time available for it. In the present study, planktonic predator-prey interactions in homogeneous isotropic turbulence are studied by a series of numerical experiments, and the effects on the capture rate of turbulence, range of predator's detection of prey, minimum pursuit time (in which the predator identify, approach, and attack the prey), and predator's motility are closely investigated. The results clearly show that there exists indeed an optimum level of relative motion between predator and prey maximizing the capture rate and that the level depends on the turbulence level and the behavioral characteristics of the predator. We also discuss the characteristics of the capture probability (the ratio of capture to encounter rates) and the contact time (the time over which a predator and its prey stay in contact), which are fundamental parameters required in understanding and modeling the planktonic feeding process.
