The impact of parasites on the life history evolution of guppies (Poecilia reticulata):: The effects of host size on parasite virulence
The impact of parasites on the life history evolution of guppies (Poecilia reticulata):: The effects of host size on parasite virulence
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DOI：
10.1016/j.ijpara.2007.04.013
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发表时间：
2007-11-01
影响因子：
4
通讯作者：
van Oosterhout, C.
中科院分区：
文献类型：
--
作者：
Cable, J.;van Oosterhout, C.
在特立尼达的天然孔雀鱼（Poecilia reticulata）种群中，Gyrodactylus寄生虫区系存在较大的时空差异。在不同的生境中，当地寄生虫的选择压力会对这些鱼类的生活史进化产生不同的影响。在此，我们在实验室用三种旋虫菌株感染了三个孔雀鱼种群，并通过全因子设计记录寄生虫数量和宿主死亡率来监测感染情况。孔雀鱼种群和寄生虫品系的起源以及宿主的大小解释了宿主存活率的显著差异。体型较大的鱼类携带的寄生虫数量最多，死亡率最高，这表明寄生虫介导的选择可能倾向于较小的表现型，可能通过限制间隙的捕食者、配偶选择和雌性繁殖力来抵消选择压力。我们观察到不同寄生虫菌株之间的毒力存在显著差异，其中人工饲养的实验菌株（Gt3）导致宿主死亡率最高，而最大负荷仅相对较低。这表明，对圈养环境的适应和/或近亲繁殖的抑制可能会改变这种圈养繁殖的寄生虫的毒力。不同种群的孔雀鱼存活率存在显著差异，下阿里波河大种群的受感染孔雀鱼的存活率高于上阿里波河小种群和遗传多样性较差的种群。(c) 2007年澳大利亚寄生虫学学会Elsevier Ltd.出版。版权所有。
There is large spatial and temporal variation in the Gyrodactylus parasite fauna across natural guppy (Poecilia reticulata) populations in Trinidad. The life history evolution of these fish could be affected differently in the various habitats depending on the local parasite selection pressure. Here, we experimentally infected three guppy populations with three gyrodactylid strains in the laboratory and monitored the infection by recording the number of parasites and host mortality in a full factorial design. The origin of the guppy population and parasite strain, and the size of the hosts explained significant variation in the survival of hosts. Larger fish carried the highest parasite loads and experienced the highest mortality rates, which suggests that parasite-mediated selection may favour smaller phenotypes, possibly counter-balancing selection pressures by gape-limited predators, mate choice and female fecundity. We observed significant variation in virulence between parasite strains with the captive-bred experimental strain (Gt3) causing the highest mortality of hosts whilst reaching only relatively low maximum burdens. This suggests that adaptations to the captive environment and/or inbreeding depression may alter the virulence of such captive-bred parasites. There were significant differences in survival rate between guppy populations, with infected guppies from the large population of the Lower Aripo River showing a higher survival rate than the fish from the small and genetically less diverse Upper Aripo River population. (c) 2007 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.