A parasite's modification of host behavior reduces predation on its host.
A parasite's modification of host behavior reduces predation on its host.
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DOI：
10.1002/ece3.2748
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发表时间：
2017-03
影响因子：
2.6
通讯作者：
Livdahl TP
中科院分区：
文献类型：
--
作者：
Soghigian J;Valsdottir LR;Livdahl TP
寄生虫修改宿主行为是常见的，和文献是占主导地位的演示增强捕食寄生的猎物，导致寄生虫传播到下一个主机。我们提出了一种情况下，寄生的猎物捕食减少。尽管理论模型表明这种现象应该是常见的，但只有少数宿主-寄生虫-捕食者系统中有报道。使用系统的gregarine内共生体在宿主蚊子，我们设计的实验比较的脆弱性寄生和未寄生的蚊子幼虫捕食专性捕食蚊子幼虫，然后比较已知的行为特征的变化中存在的捕食线索。我们将三列伊蚊幼虫暴露于寄生虫Ascogregarina barretti和捕食者Toxohrynchites rutilus，并评估每个处理条件下的幼虫死亡率。此外，我们评估了行为的差异，由于感染和捕食刺激记录幼虫和评分的行为和位置内的微观世界。感染gregarines降低队列死亡率的捕食者的存在下，但寄生虫并不影响死亡率。此外，寄生虫的感染改变了行为，使得受感染的宿主比未受感染的宿主更不频繁地鞭打，并且更频繁地在微观世界中的避难所中被发现。通过减少对它们的宿主的捕食，在捕食它们的宿主的情况下，gregarines可能会充当互利主义者。这些结果说明了一种更高阶的相互作用，其中物种对（宿主-内共生体或捕食者-猎物）之间的关系因第三物种的存在而改变。
Parasite modification of host behavior is common, and the literature is dominated by demonstrations of enhanced predation on parasitized prey resulting in transmission of parasites to their next host. We present a case in which predation on parasitized prey is reduced. Despite theoretical modeling suggesting that this phenomenon should be common, it has been reported in only a few host–parasite–predator systems. Using a system of gregarine endosymbionts in host mosquitoes, we designed experiments to compare the vulnerability of parasitized and unparasitized mosquito larvae to predation by obligate predatory mosquito larvae and then compared behavioral features known to change in the presence of predatory cues. We exposed Aedes triseriatus larvae to the parasite Ascogregarina barretti and the predator Toxohrynchites rutilus and assessed larval mortality rate under each treatment condition. Further, we assessed behavioral differences in larvae due to infection and predation stimuli by recording larvae and scoring behaviors and positions within microcosms. Infection with gregarines reduced cohort mortality in the presence of the predator, but the parasite did not affect mortality alone. Further, infection by parasites altered behavior such that infected hosts thrashed less frequently than uninfected hosts and were found more frequently on or in a refuge within the microcosm. By reducing predation on their host, gregarines may be acting as mutualists in the presence of predation on their hosts. These results illustrate a higher‐order interaction, in which a relationship between a species pair (host–endosymbiont or predator–prey) is altered by the presence of a third species.