Data from: Parallel and non-parallel behavioural evolution in response to parasitism and predation in Trinidadian guppies

Natural enemies such as predators and parasites are known to shape intra-specific variability of behaviour and personality in natural populations, yet several key questions remain: (1) What is the relative importance of predation versus parasitism in shaping intra-specific variation of behaviour across generations? (2) What are the contributions of genetic and plastic effects to this behavioural divergence? And (3) to what extent are responses to predation and parasitism repeatable across independent evolutionary lineages? We addressed these questions using Trinidadian guppies (Poecilia reticulata) (1) varying in their exposure to dangerous fish predators and Gyrodactylus ectoparasites, for (2) both wild-caught F0 and laboratory-reared F2 individuals and coming from (3) multiple independent evolutionary lineages (i.e. independent drainages). Several key findings emerged. First, a population's history of predation and parasitism influenced behavioural profiles, but to different extent depending on the behaviour considered (activity, shoaling or boldness). Second, we had evidence for some genetic effects of predation regime on behaviour, with differences in activity of F2 laboratory-reared individuals, but not for parasitism, which had only plastic effects on the boldness of wild-caught F0 individuals. Third, the two lineages showed a mixture of parallel and non-parallel responses to predation/parasitism, with parallel responses being stronger for predation than for parasitism and for activity and boldness than for shoaling. These findings suggest that different sets of behaviours provide different pay-offs in alternative predation/parasitism environments, and that parasitism have more transient effects in shaping intra-specific variation of behaviour than does predation.已知捕食者、寄生虫等天敌对自然种群内行为与个性的种内变异（intra-specific variability）具有塑造作用，但目前仍有若干核心问题亟待解答：（1）在跨世代的行为塑造过程中，捕食与寄生二者对种内行为变异的相对重要性如何？（2）遗传效应（genetic effects）与可塑性效应（plastic effects）分别对该行为分化作出了何种贡献？（3）在独立演化支系（evolutionary lineages）间，针对捕食与寄生的响应在多大程度上具有可重复性？本研究以特立尼达孔雀鱼（Trinidadian guppies, Poecilia reticulata）为研究对象，其样本具备三项特征：其一，个体暴露于危险鱼类捕食者与三代虫属外寄生虫（Gyrodactylus ectoparasites）的程度存在差异；其二，研究涵盖野生捕获的F0代与实验室繁育的F2代个体；其三，样本来自多个独立演化支系（即独立流域）。本研究得到若干核心发现：其一，种群的捕食与寄生经历会影响其行为谱（behavioural profiles），但影响程度因所考察的行为类型——活动量、集群性（shoaling）或大胆度（boldness）——而异。其二，研究发现捕食制度对行为存在一定遗传效应：实验室繁育的F2代个体的活动量存在显著差异，但寄生并未表现出此类遗传效应——仅对野生捕获的F0代个体的大胆度存在可塑性影响。其三，两个演化支系对捕食/寄生的响应兼具平行响应（parallel responses）与非平行特征：平行响应在捕食情境下较寄生情境更为显著，且在活动量与大胆度上较集群性更为突出。上述研究结果表明，在不同的捕食/寄生环境中，不同类型的行为会产生差异化的适合度收益（pay-offs），且相较于捕食作用，寄生作用对行为种内变异的塑造效应更为短暂。