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（conspecifics）或亲属）建立社交关联，可带来诸多益处。介导此类识别的一类机制是印记（imprinting）：即个体对发育阶段遭遇的信号形成长期记忆。通常而言，幼体会对邻近个体的信号产生印记，并在后续阶段倾向于与匹配其“识别模板（recognition template）”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会决策——例如，若个体对感染直接传播疾病的同种个体的信号产生印记，便可能出现此类问题。为探究印记在疾病传播感官生态学中的作用，我们将幼年孔雀鱼（Poecilia reticulata）分别暴露于健康同种个体的信号，或是感染直接传播寄生虫三代虫（Gyrodactylus turnbulli）所致疾病的个体的信号环境中。在二分选择实验中，成年“疾病印记组”孔雀鱼更倾向于与感染三代虫的同种个体的化学信号建立关联，而“健康印记组”孔雀鱼则更偏好未感染个体的信号。仅当刺激鱼处于感染后期时，此类响应才会显现，这表明印记个体所响应的是与疾病相关的信号，而非单纯的感染信号。我们讨论了适应不良的印记如何在社会性宿主的自然种群中促进疾病传播。