FOOD THRESHOLDS AND BODY SIZE IN CLADOCERANS
FOOD THRESHOLDS AND BODY SIZE IN CLADOCERANS
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DOI：
10.1038/343638a0
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发表时间：
1990-02-15
期刊：
影响因子：
64.8
通讯作者：
GLIWICZ, ZM
中科院分区：
文献类型：
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作者：
GLIWICZ, ZM
根据体型效率假说，体型是决定自然界浮游动物相对丰度的最重要因素之一。首先，体型较大的物种更容易被捕食，因为它们会在视觉上喂食浮游鱼类。其次，它们是资源的优秀竞争者，能够在较低的食物浓度下生长和繁殖。但是，尽管第一个假设已经被许多实地和实验数据所证实（参见参考文献2-4），第二个建议缺乏实验证据，并且经常受到质疑。我现在提供了来自8种滤食性物种（水蚤科）的实验数据，这些数据有力地支持了尺寸效率假说中竞争方面的基础假设。这些数据表明，在稳定状态和低死亡率的条件下，大型物种所需的食物浓度阈值要低于小型物种。
ACCORDING to the size–efficiency hypothesis1, body size is one of the most important determinants of the relative abundance of planktonic animals in nature. First, large-bodied species are more vulnerable to predation by visually feeding planktivorous fishes. Second, they are superior competitors for resources, being able to grow and reproduce at lower food concentrations. But whereas the first assumption has been confirmed by many field and experimental data (for review see refs 2–4), the second suggestion lacks experimental evidence and has been frequently questioned5-12. I now present experimental data from eight filter-feeding species (familyDaphnidae) that strongly support the cornerstone assumption of the competitive aspect of the size-efficiency hypothesis. These data show that the threshold food concentration necessary to assure that assimilation equals respiration13, is lower for the large-bodied species than it is for the small-bodied species under steady-state and low-mortality conditions.