Social trematode parasites increase standing army size in areas of greater invasion threat
Social trematode parasites increase standing army size in areas of greater invasion threat
复制标题
DOI：
10.1098/rsbl.2019.0765
复制
发表时间：
2020-02
期刊：
影响因子：
3.3
通讯作者：
Emlyn J. Resetarits;M. Torchin;R. Hechinger
中科院分区：
文献类型：
--
作者：
Emlyn J. Resetarits;M. Torchin;R. Hechinger
生物体或社会资源有限，导致繁殖和防御之间的重要权衡。鉴于这种权衡，最优分配理论预测，对于具有士兵种姓的动物社会，对士兵的分配应该反映当地的外部威胁。虽然威胁强度和士兵分配在本质上可能存在很大差异，但我们目前缺乏强有力的证据表明威胁的空间变化可以驱动士兵分配的相应变化。加州角蜗牛的吸虫寄生虫的多样性公会提供了一个有用的系统来解决这个问题。其中一些物种在宿主中形成殖民地，并进行生殖分工，包括士兵种姓。士兵是非生殖性的，专门从事防御、攻击和杀死入侵的寄生虫。我们量化的入侵威胁和士兵分配168吸虫菌落属于6个物种在26个站点分布在温带和热带地区的10个河口。入侵威胁的空间变化与多个寄生虫物种的相对士兵数量预测相匹配。士兵分配与入侵威胁在精细的空间尺度，这表明分配至少部分是诱导。这些结果可能是第一个明确的文件之间的空间相关性分配到任何类型的种姓和生物选择剂。
Organisms or societies are resource limited, causing important trade-offs between reproduction and defence. Given such trade-offs, optimal allocation theory predicts that, for animal societies with a soldier caste, allocation to soldiers should reflect local external threats. Although both threat intensity and soldier allocation can vary widely in nature, we currently lack strong evidence that spatial variation in threat can drive the corresponding variation in soldier allocation. The diverse guild of trematode parasites of the California horn snail provides a useful system to address this problem. Several of these species form colonies in their hosts with a reproductive division of labour including a soldier caste. Soldiers are non-reproductive and specialized in defence, attacking and killing invading parasites. We quantified invasion threat and soldier allocation for 168 trematode colonies belonging to six species at 26 sites spread among 10 estuaries in temperate and tropical regions. Spatial variation in invasion threat was matched as predicted by the relative number of soldiers for multiple parasite species. Soldier allocation correlated with invasion threat at fine spatial scales, suggesting that allocation is at least partly inducible. These results may represent the first clear documentation of a spatial correlation between allocation to any type of caste and a biotic selective agent.