浮游动物在捕食压力下的昼夜垂直迁移与最优食物摄取策略:模拟分析

DVM OF ZOOPLANKTON UNDER PREDATION PRESSURE AND OPTIMAL FOOD INTAKE STRATEGY: SIMULATION ANALYSIS

提出一个浮游动物昼夜垂直迁移的风险收益模型 ,其迁移运动的动力来自于浮游动物获取风险收益的最大值 ,即以尽可能小的死亡代价获取尽可能多的食物。风险收益反映浮游动物权衡死亡危险和食物摄取的结果 ,不仅是外界环境因子温度、食物和捕食压力的函数 ,也受到动物内部状态因子年龄的影响。本模型在一个简化的、典型的温带地区夏季分层水体环境中的运行结果表明 ,通过检测环境因子的变化 ,浮游动物借助于昼夜垂直迁移逃避捕食压力的同时能够实现最优的食物摄取量 ,同时 ,动物年龄不同 。

A model of venturous revenue for diel vertical migration (DVM) of zooplankton is developed, which is motivated by zooplankter chasing the maximum value of venturous revenue, i.e., cropping as much food at as less cost of mortality as possible. Venturous revenue, indicating the tradeoffs between food intake and mortality risk, is not only a function of environmental factors such as temperature, food abundance and predation pressure, but also a factor affected by age. The simulated results from running the model in a simplified typical summer stratified water environment in temperate region suggest that a zooplankter through detecting the variations of environmental factors can achieve the optimal food intake strategy by DVM against predation pressure, and that the pattern of DVM is different with different age of the zooplanker.