Mechanisms, phenotypic plasticity and genotypic determination of thermal tolerance and related properties in Daphnia and Leptodora kindtii:: consequences for temperature impacts on food web interactions

全球变暖可能通过对其成员的生理系统产生直接或间接影响而对水生生态系统产生深远影响。水蚤属在几乎所有现存淡水的生态中起着核心作用，而Chaoborus幼虫是水蚤的主要无脊椎动物捕食者。为了从机理上了解热效应对水蚤和斑点跳蚤幼虫的影响，将结合现场数据分析、生理生化调查和回顾研究：调查表型驯化的季节性变化以及克隆结构和克隆特有的热耐性，以便评估未来全球变暖的生态后果。将分析生理生化机制、耐热性程度以及与生理适合度相关的性状，并据此评估改变热性能的成本或收益。这些结果将与季节期间的环境条件联系在一起。了解温度对水蚤和湄公鱼的性能和适合度的作用将使我们能够首先预测，如果具体地说，这对捕食者-捕食者对可能由于它们的热性能和能力的不匹配而在全球变暖时彼此分开生长，第二，不同温度下的水蚤的一般特性或策略将如何与食物资源的时间丰富相匹配。对不同的热适应，但密切相关的克隆和物种的比较，将得出对水蚤的总体看法。

Global warming may have far-reaching effects on aquatic ecosystems through direct or indirect effects on the physiological systems of its members. The genus Daphnia plays a central role in the ecology of almost all standing freshwater, and Chaoborus larvae are prominent invertebrate predators of Daphnia. For a mechanistic understanding of thermal effects on Daphnia and Chaoborus larvae, field data analysis, physiological and biochemical investigations and retrospective studies will be brought together: investigation of the seasonal changes of phenotypic acclimatization as well as of clonal structure and clone-specific thermal tolerance will allow to evaluate future ecological consequences of global warming. The physiological and biochemical mechanisms and the degree of thermal tolerance as well as traits related to physiological fitness will be analysed and accordingly, costs or benefits of a changed thermal performance will be assessed. These results will be linked with the environmental conditions during the seasons. An understanding of the role of temperature for the performance and fitness of Daphnia and Chaoborus will allow to predict firstly, if specifically this prey-predator pair may grow apart from each other at global warming due to a mismatch of their thermal performances and capacities, and secondly, how the general properties or strategies of Daphnia at different temperatures will match the temporal abundance of food resources. A general view on Daphnia will be derived from the comparison of differently thermally adapted, yet closely related clones and species.