Lewis D M, Pedley T J
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Silver Street, Cambridge, CB3 9EW, UK.
J Theor Biol. 2001 Jun 7;210(3):347-65. doi: 10.1006/jtbi.2001.2310.
The importance of predation in regulating the size of competing plankton and larval fish populations has long been appreciated. However, it has only recently been recognized that turbulence must have a significant influence on predator-prey interactions because most rival species of microorganisms co-exist in oceanic or fast moving fresh water flows. Turbulence is likely to influence predation strategies in two ways. The extra energy imparted to a micro-organism from the flow field will enhance the number of encounters or "contacts" between predators and prey. At the same time, because the velocity of a predator relative to its potential prey will be increased, the time-scale over which a capture must be completed is reduced. Balancing the benefits of extra encounters with the drawbacks of more difficult captures, will dictate an optimal predation strategy, either foraging behaviour or ambush feeding, on the predator. This will depend on its own and the prey's swimming capabilities, as well as the characteristics of the turbulent environment. In this paper some previous work, examining the increased encounter rate in turbulence, will be extended to look at the capture problem. The main proposal is that the capture event should be encapsulated in a capture probability function, from which the optimal predation strategy can be derived. As an illustration, plausible capture probability functions will be postulated and the resulting predictions tested against numerical simulations carried out in a turbulent-like flow field. Good agreement between the predictions and the simulations is demonstrated.
长期以来，捕食在调节竞争性浮游生物和幼鱼种群数量方面的重要性已得到认可。然而，直到最近人们才认识到，湍流必定会对捕食者与猎物之间的相互作用产生重大影响，因为大多数微生物竞争物种共存于海洋或快速流动的淡水流中。湍流可能通过两种方式影响捕食策略。流场赋予微生物的额外能量会增加捕食者与猎物之间的相遇次数或“接触”次数。与此同时，由于捕食者相对于其潜在猎物的速度会增加，完成捕获所需的时间尺度会缩短。在额外相遇的益处与更难捕获的弊端之间进行权衡，将决定捕食者的最优捕食策略，即觅食行为或伏击式捕食。这将取决于捕食者自身以及猎物的游泳能力，还有湍流环境的特征。在本文中，一些先前研究湍流中相遇率增加的工作将得到扩展，以探讨捕获问题。主要提议是，捕获事件应包含在一个捕获概率函数中，由此可以推导出最优捕食策略。作为一个例证，将假定合理的捕获概率函数，并将所得预测结果与在类似湍流流场中进行的数值模拟进行对比检验。结果表明预测结果与模拟结果吻合良好。
