Friesen Olwyn C, Poulin Robert, Lagrue Clément
Department of Zoology University of Otago Dunedin New Zealand.
Ecol Evol. 2017 May 22;7(13):4682-4693. doi: 10.1002/ece3.3062. eCollection 2017 Jul.
Effects of parasites on individual hosts can eventually translate to impacts on host communities. In particular, parasitism can differentially affect host fitness among sympatric and interacting host species. We examined whether the impact of shared parasites varied among host species within the same community. Specifically, we looked at the impacts of the acanthocephalan , the trematodes and , and the nematode , on three host species: the amphipods, and , and the isopod, . We assessed parasite infection levels in the three host species and tested for effects on host survival, behavior, probability of pairing, and fecundity. and were most abundant in but had no effect on its survival, whereas they negatively affected the survival of , the other amphipod. Female amphipods carrying young had higher and abundance than those without, yet the number of young carried was not linked to parasite abundance. Behavior of the isopod was affected by infection; more heavily infected individuals were more active. moved longer distances when abundance of was lower, yet no relationship existed with respect to infection by both and . The differential effects of parasites on amphipods and isopods may lead to community-wide effects. Understanding the consequences of parasitic infection and differences among host species is key to gaining greater insight into the role of parasite mediation in ecosystem dynamics.
寄生虫对个体宿主的影响最终可能转化为对宿主群落的影响。特别是，寄生现象会对同域共存且相互作用的宿主物种的适合度产生不同影响。我们研究了同一群落内共享寄生虫的影响在宿主物种间是否存在差异。具体而言，我们观察了棘头虫、吸虫和线虫对三种宿主物种的影响：两种双壳纲动物和一种等足目动物。我们评估了这三种宿主物种的寄生虫感染水平，并测试了其对宿主生存、行为、配对概率和繁殖力的影响。[两种寄生虫名称]在[第一种双壳纲动物]中最为常见，但对其生存没有影响，然而它们对另一种双壳纲动物[第二种双壳纲动物]的生存产生了负面影响。携带幼体的雌性双壳纲动物体内[两种寄生虫名称]的丰度高于未携带幼体的雌性，但携带的幼体数量与寄生虫丰度无关。等足目动物[等足目动物名称]的行为受到[一种寄生虫名称]感染的影响；感染程度较重的个体更活跃。当[一种寄生虫名称]的丰度较低时，[等足目动物名称]移动的距离更长，但与[另一种寄生虫名称]的感染情况无关。寄生虫对双壳纲动物和等足目动物的不同影响可能会导致整个群落层面的效应。了解寄生虫感染的后果以及宿主物种间的差异，是更深入洞察寄生虫介导在生态系统动态中作用的关键。
