The ubiquitous oceanic copepod Calanus finmarchicus is the major link between primary producers and important fish stocks in the North Atlantic Ocean and adjacent seas. Despite over a century of research on growth and development of this key species, the effect of predation risk on these processes remains elusive. We tested how food level and chemical cues from a fish predator influence growth and development of C. finmarchicus, using a predator naïve laboratory population. Copepods reached adult stage earlier both in response to high food and to predator cues in our experiment. High food also increased growth and lipid accumulation. In contrast, perceived predation risk triggered reduced size and lipid fullness, indicating a decoupling of growth and development rates. Our results demonstrate that chemical predator cues can influence life history strategies in C. finmarchicus, and suggest that present and future patterns in oceanic zooplankton size and population dynamics may also reflect differences in predation risk.

中文翻译：

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捕食风险改变了海洋桡足类动物的生活史策略

无处不在的海洋桡足类 Calanus finmarchicus 是北大西洋和邻近海域初级生产者和重要鱼类种群之间的主要联系。尽管对这一关键物种的生长和发育进行了一个多世纪的研究，但捕食风险对这些过程的影响仍然难以捉摸。我们使用捕食者幼稚的实验室种群测试了来自鱼类捕食者的食物水平和化学线索如何影响 C. finmarchicus 的生长和发育。在我们的实验中，桡足类对高食和捕食者线索的反应较早达到成年阶段。高食物还增加了生长和脂质积累。相比之下，感知到的捕食风险引发了体积减小和脂质丰满度的降低，表明生长和发育速度脱钩。