Data from: Water mold infection but not paternity induces selective filial cannibalism in a goby

Many animals heavily invest in parental care but still reject at least some of their offspring. Although seemingly paradoxical, selection can favor parents to neglect offspring of particularly low reproductive value, for example, because of small survival chances. We here assess whether filial cannibalism (FC), where parents routinely eat some of their own young, is selective in response to individual offspring reproductive value. We performed two independent laboratory experiments in the common goby (Pomatoschistus microps) to test whether caring fathers preferentially cannibalize eggs of a given infection history and paternity. While males did not discriminate kin from nonkin eggs, they consumed significantly more eggs previously exposed to water mold compared to uninfected eggs. Our findings clearly show that parents differentiate between eggs based on differences in egg condition, and thus complement the prevailing view that FC arises for energetic reasons. By preventing the spread of microbial infections, the removal of molded eggs can constitute an important component of parental care and may represent a key driver of selective FC in a wide array of parental fish.

诸多动物会在亲代抚育上投入大量资源，但仍会舍弃至少一部分后代。这一现象看似矛盾，实则自然选择会倾向于那些舍弃繁殖价值尤其低下的后代的亲本——例如存活概率极低的后代。本研究旨在探究亲子相食（filial cannibalism，FC）——即亲本主动取食部分自身后代的行为——是否会根据后代个体的繁殖价值产生选择性发生。我们以普通缟虾虎鱼（Pomatoschistus microps）为研究对象，开展了两项独立的室内实验，以验证抚育子代的雄性亲鱼是否会优先取食具有特定感染史与父权背景的鱼卵。尽管雄性亲鱼并未区分亲缘与非亲缘鱼卵，但相较于未感染的鱼卵，它们会显著更多地取食先前暴露于水霉菌的鱼卵。本研究结果清晰表明，亲本可依据鱼卵状态差异进行选择性取食，这补充了当前认为亲子相食源于能量需求的主流观点。通过阻止微生物感染扩散，移除感染水霉菌的鱼卵可成为亲代抚育的重要组成部分，也可能是广泛分布于各类抚育性鱼类中的选择性亲子相食行为的关键驱动因素。