Temporally consistent species differences in parasite infection but no evidence for rapid parasite-mediated speciation in Lake Victoria cichlid fish

Parasites may have strong eco-evolutionary interactions with their hosts. Consequently, they may contribute to host diversification. The radiation of cichlid fish in Lake Victoria provides a good model to study the role of parasites in the early stages of speciation. We investigated patterns of macroparasite infection in a community of 17 sympatric cichlids from a recent radiation and 2 older species from 2 non-radiating lineages, to explore the opportunity for parasite-mediated speciation. Host species had different parasite infection profiles, which were only partially explained by ecological factors (diet, water depth). This may indicate that differences in infection are not simply the result of differences in exposure, but that hosts evolved species-specific resistance, consistent with parasite-mediated divergent selection. Infection was similar between sampling years, indicating that the direction of parasite-mediated selection is stable through time. We morphologically identified ...

寄生虫（Parasites）与其宿主之间可形成强烈的生态进化互作，进而可能推动宿主类群的分化。维多利亚湖慈鲷（cichlid fish）的演化辐射为探究寄生虫在物种形成（speciation）早期阶段的作用提供了优质研究模型。本研究针对由17种来自近期演化辐射类群的同域分布（sympatric）慈鲷，以及2个隶属于2个非辐射演化支的古老物种组成的群落，调查了其大型寄生虫（macroparasite）的感染模式，以探究寄生虫介导的物种形成（parasite-mediated speciation）的潜在可能性。不同宿主物种的寄生虫感染谱存在显著差异，且该差异仅能通过生态因子（饮食、水深）得到部分解释。这一结果或表明，感染差异并非单纯源于宿主间的感染暴露差异，而是宿主演化出了物种特异性抗性，这与寄生虫介导的歧化选择理论相符。不同采样年份的感染模式较为相似，表明寄生虫介导的选择方向在时间尺度上保持稳定。本研究通过形态学方法鉴定了……