Data from: Imprinting can cause a maladaptive preference for infectious conspecifics

Recognizing and associating with specific individuals, such as conspecifics or kin, brings many benefits. One mechanism underlying such recognition is imprinting: the long-term memory of cues encountered during development. Typically, juveniles imprint on cues of nearby individuals and may later associate with phenotypes matching their ‘recognition template’. However, phenotype matching could lead to maladaptive social decisions if, for instance, individuals imprint on the cues of conspecifics infected with directly transmitted diseases. To investigate the role of imprinting in the sensory ecology of disease transmission, we exposed juvenile guppies, Poecilia reticulata, to the cues of healthy conspecifics, or to those experiencing disease caused by the directly transmitted parasite Gyrodactylus turnbulli. In a dichotomous choice test, adult ‘disease-imprinted’ guppies preferred to associate with the chemical cues of G. turnbulli-infected conspecifics, whereas ‘healthy-imprinted’ guppies preferred to associate with cues of uninfected conspecifics. These responses were only observed when stimulus fish were in late infection, suggesting imprinted fish responded to cues of disease, but not of infection alone. We discuss how maladaptive imprinting may promote disease transmission in natural populations of a social host.识别并与特定个体（如同种个体或亲属）建立社交关联，可带来诸多益处。支撑此类识别的核心机制之一为印记学习（imprinting）：即个体在发育阶段所遭遇的线索形成的长期记忆。通常而言，幼体会对邻近个体的相关线索形成印记，并在后续成长阶段倾向于与契合其‘识别模板’的表型个体建立社交关联。然而，表型匹配可能引发适应不良的社交决策——例如，若个体对感染了直接传播性疾病的同种个体的线索形成印记，便可能出现此类问题。为探究印记学习在疾病传播感官生态学中的作用，我们将幼年孔雀鱼（Poecilia reticulata）暴露于两类线索环境：一类为健康同种个体的线索，另一类为受直接传播寄生虫Gyrodactylus turnbulli引发的疾病感染个体的线索。在二分选择试验（dichotomous choice test）中，成年‘疾病印记型’孔雀鱼更倾向于与感染Gyrodactylus turnbulli的同种个体的化学线索建立关联，而‘健康印记型’孔雀鱼则更偏好与未感染个体的化学线索建立社交关联。此类响应仅在作为刺激源的鱼处于感染后期时才可被观测到，这表明经印记处理的个体的响应针对的是疾病相关线索，而非单纯的感染信号。我们还讨论了适应不良的印记学习可能如何在社会性宿主的自然种群中促进疾病传播。