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Hazardous host-finding: Comparative study of transmission abilities and predator evasion in parasites

危险宿主发现：寄生虫传播能力和捕食者逃避的比较研究

基本信息

批准号：
325767530
负责人：
Dr. Christian Selbach
金额：
--
依托单位：
Department of Zoology
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/325767530?language=en
关键词：
Hazardous host finding Comparative study

项目摘要

Parasites are important and integral elements of ecosystems. The successful transmission from one host to another plays a decisive role for the completion of the life cycle (and thus for the fitness) of parasites. Due to the differences in life cycles and environmental conditions, parasite transmission stages have evolved a wide diversity of sizes, shapes or behaviors, even among closely related taxa. With 25,000 species parasitizing a variety of hosts, digenetic trematodes are ideal model systems to study the ecology and evolution of mobile transmission stages because they are the most common eukaryotic pathogens in aquatic systems and there is huge variation in the size and morphology of their free-living transmission stages, known as cercariae. Furthermore, recent studies have stressed the role of the cercariae as important energy resources for possible predators. The short-lived cercariae must therefore be able to find and infect a suitable host within a limited time window whilst evading predators. Both factors influence the success of individual parasite species and should thus shape the parasite communities of ecosystems. However, to what extent this happens under natural conditions is still poorly understood and key issues remain untested, e.g. what role predators have on the transmission success of individual trematode species, and whether or not this may explain different trematode community structures in environments rich in predatory species. Furthermore, climate change is believed to have significant impact on ecosystems and its parasites, and some pathogens might benefit from these developments. However, we do not yet know specifically how parasite transmission strategies will be affected by changing environmental conditions. The project aims at testing the hypotheses that cercarial transmission and predation shape trematode communities, and that temperature changes will have significant effects on these processes. In order test this, standardized laboratory and mesocosm experiments on the specific dispersal capabilities of free-swimming cercariae and the effects of their main predators in freshwater environments will be performed under different temperature scenarios. Connecting these results with available data on host, parasite and predator community structure from well-sampled freshwaters in Otago, New Zealand will provide valuable insight into the structuring forces that determine parasite dispersal and thus shape these ecosystems parasite communities.

寄生虫是生态系统的重要组成部分。从一个宿主到另一个宿主的成功传播对于寄生虫生命周期的完成（从而对于适应性）起着决定性作用。由于生命周期和环境条件的差异，寄生虫传播阶段已经进化出广泛多样的大小，形状或行为，甚至在密切相关的类群之间。复殖吸虫是水生系统中最常见的真核病原体，其寄生于各种宿主的25，000种吸虫是研究移动的传播阶段的生态学和进化的理想模式系统，因为它们是水生系统中最常见的真核病原体，并且其自由生活的传播阶段（称为尾蚴）的大小和形态存在巨大差异。此外，最近的研究强调了尾蚴作为可能的捕食者的重要能源的作用。因此，短寿命的尾蚴必须能够在有限的时间窗口内找到并感染合适的宿主，同时躲避捕食者。这两个因素都影响到单个寄生虫物种的成功，因此应该塑造生态系统的寄生虫群落。然而，在何种程度上，这发生在自然条件下仍然知之甚少，关键问题仍然没有得到验证，例如捕食者对单个吸虫物种的传播成功有什么作用，以及这是否可以解释在捕食性物种丰富的环境中不同的吸虫群落结构。此外，气候变化被认为对生态系统及其寄生虫产生重大影响，一些病原体可能会从这些发展中受益。然而，我们还不知道寄生虫传播策略将如何受到不断变化的环境条件的影响。该项目旨在检验以下假设：尾蚴传播和捕食塑造吸虫群落，温度变化将对这些过程产生重大影响。为了检验这一点，将在不同的温度情景下进行标准化实验室和围隔实验，研究自由游动尾蚴的特定扩散能力及其主要捕食者在淡水环境中的影响。连接这些结果与现有的数据主机，寄生虫和捕食者群落结构，从采样良好的淡水在奥塔哥，新西兰将提供有价值的洞察力的结构化力量，决定寄生虫扩散，从而塑造这些生态系统寄生虫群落。