Host sex and ectoparasites choice: preference for, and higher survival on female hosts
Host sex and ectoparasites choice: preference for, and higher survival on female hosts
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DOI：
10.1111/j.1365-2656.2007.01255.x
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发表时间：
2007-07-01
影响因子：
4.8
通讯作者：
Arlettaz, Raphael
中科院分区：
文献类型：
--
作者：
Christe, Philippe;Glaizot, Olivier;Arlettaz, Raphael
1. 在许多哺乳动物中，寄生虫感染水平的性别差异是一个普遍规律，雄性通常比雌性更容易受到感染。对寄生虫的性别特异性暴露，例如通过性别之间和性别内部不同的社会聚集模式介导，以及雄激素水平与免疫防御之间的负相关关系，被认为在这种模式中起主要作用。生殖雌蝙蝠在母性栖息地紧密地群居在一起，而非繁殖雌蝙蝠和雄蝙蝠通常单独栖息。因此，蝙蝠是研究性别特异性社会和空间聚集对寄生虫感染策略影响的理想模型。我们首先比较了宿主-寄生虫系统的流行率和寄生虫强度，该系统由密切相关的外寄生螨（Spinturnix spp.）和它们的宿主——五种欧洲蝙蝠组成。然后，我们比较了大耳蝠和小耳蝠混合群体中幼雄性和雌性的寄生水平。在所有五个研究物种中，由于群体聚集，成年雌性的患病率高于成年雄性。在研究的五个物种中，有三个物种的雌性寄生虫强度显著高于雌性。种群中雌雄幼螨的流行率和数量无显著差异。为了评估所观察到的性别偏向寄生是否仅仅是由宿主暴露的差异引起的，或者是由寄生虫主动选择的结果，我们进行了寄生虫对雄性和雌性道本托尼肌炎的短期偏好和长期生存的实验室实验。当寄生虫面对雄性和雌性时，它们优先选择雌性寄主，而在成年雌性和亚成年雄性之间没有选择差异。最后，我们发现雌虫的存活率明显高于雄虫。我们的研究表明，社会和空间聚集有利于性别偏见的寄生，这可能仅仅是寄生对更有利可图的宿主进行主动和适应性选择的结果。
1. Sex differences in levels of parasite infection are a common rule in a wide range of mammals, with males usually more susceptible than females. Sex-specific exposure to parasites, e.g. mediated through distinct modes of social aggregation between and within genders, as well as negative relationships between androgen levels and immune defences are thought to play a major role in this pattern.2. Reproductive female bats live in close association within clusters at maternity roosts, whereas nonbreeding females and males generally occupy solitary roosts. Bats represent therefore an ideal model to study the consequences of sex-specific social and spatial aggregation on parasites' infection strategies.3. We first compared prevalence and parasite intensities in a host-parasite system comprising closely related species of ectoparasitic mites (Spinturnix spp.) and their hosts, five European bat species. We then compared the level of parasitism between juvenile males and females in mixed colonies of greater and lesser mouse-eared bats Myotis myotis and M. blythii. Prevalence was higher in adult females than in adult males stemming from colonial aggregations in all five studied species. Parasite intensity was significantly higher in females in three of the five species studied. No difference in prevalence and mite numbers was found between male and female juveniles in colonial roosts.4. To assess whether observed sex-biased parasitism results from differences in host exposure only, or, alternatively, from an active, selected choice made by the parasite, we performed lab experiments on short-term preferences and long-term survival of parasites on male and female Myotis daubentoni. When confronted with adult males and females, parasites preferentially selected female hosts, whereas no choice differences were observed between adult females and subadult males. Finally, we found significantly higher parasite survival on adult females compared with adult males.5.Our study shows that social and spatial aggregation favours sex-biased parasitism that could be a mere consequence of an active and adaptive parasite choice for the more profitable host.