Who is eating whom? Morphology and feeding type determine the size relation between planktonic predators and their ideal prey
Who is eating whom? Morphology and feeding type determine the size relation between planktonic predators and their ideal prey
复制标题
谁在吃谁？
DOI：
10.3354/meps09502
复制
发表时间：
2012
影响因子：
2.5
通讯作者：
K. Wirtz
中科院分区：
文献类型：
--
作者：
K. Wirtz
身体大小决定了生物在浮游生物食物网中的位置。因此，捕食者与其最佳猎物之间的质量或直径比是基于大小的模型的核心要素，这些模型试图将不同营养水平的消费者群体联系起来。尽管在浮游生物生态学的大小为基础的方法复兴，然而，这种关系仍然缺乏一个通用的，也是机械健全的公式。根据经验得出的这个比值的恒定值不能描述特定捕食者大小类的最佳猎物分布的广泛分散，特别是在中型浮游动物范围内。在这项研究中，我提出了一个给定的形态计量比之间的摄食相关的机构和总的身体体积减少时，捕食者的大小增加。该比率降低是由于较大生物体中用于维持体内转运的结构组分的额外需求。非等距标度导致最佳猎物大小对捕食者直径的非线性依赖性。这种依赖性定义了一种平均关系，该平均关系使得能够定量地定义馈送模式。这个新的性状变量解释了最佳猎物直径的变异性的一个组成部分，这是独立的捕食者直径。摄食方式作为一种性状，可以解释为放牧过程中的活动，主要是游泳或摄食电流产生的速度调节。摄食模式与经典的捕食者大小特征相一致，精确地决定了最佳猎物大小。这是广泛的测试，使用整个浮游生物领域的文献数据。该理论预测，在较大的消费物种中，进食活动会增加。它阐明了浮游动物群落组成的连续变化如何与平均体型和摄食方式的弱耦合变化联系在一起。
Body size determines the position of or- ganisms in plankton food webs. The mass or diameter ratio between predators and their optimal prey is therefore a central element of size-based models, which attempt to link consumer groups across trophic levels. Despite a renaissance of size-based approaches in plankton ecology, however, this relation still lacks a generic and also mechanistically sound formulation. An empirically derived constant value of this ratio cannot describe the wide scatter in optimal prey di- ameter for specific predator size classes, especially in the mesozooplankton range. In this study, I propose that a given morphometric ratio between feeding- related apparatus and total body volume decreases when predator size increases. This ratio decrease is due to the additional need for structural components in larger organisms for maintaining intra-body trans- port. Non-isometric scaling results in a non-linear de- pendency of optimal prey size on predator diameter. This dependency defines an average relation which enables the quantitative definition of feeding mode. This new trait variable explains a component of the variability in optimal prey diameter that is indepen- dent of predator diameter. Feeding mode as a trait can be interpreted as activity during grazing, mostly in terms of speed regulation in swimming or in feed- ing-current generation. Feeding mode, in concert with the classical trait predator size, accurately deter- mines optimal prey size. This was extensively tested using literature data for the entire plankton domain. The theory predicts increasing feeding activity in larger consumer species. It elucidates how succes- sional shifts in the composition of zooplankton com- munities are linked to weakly coupled changes in mean body size and feeding mode.