Data for: Sex matters: Predator presence induces sexual dimorphism in a monomorphic prey, from stress genes to morphological defenses

Inducible defences allow prey to increase survival chances when predators are present while avoiding unnecessary costs in their absence. Many studies report considerable inter-individual variation in inducible-defence expression, yet what underlies this variation is poorly understood. A classic vertebrate example of a predator‐induced morphological defence is the increased body depth in crucian carp (Carassius carassius), which reduces the risk of predation from gape‐size limited predators. Here, we report that among-individual variation in morphological defence expression can be linked to sex. We documented sexual dimorphism in lakes in which crucian carp coexisted with predators, where females showed shallower relative body depths than males, but not in a predator-free lake. When exposing crucian carp from a population without predators to perceived predation risk in a laboratory environment (presence/absence of pike, Esox lucius), we found that males expressed significantly greater m...诱导防御（inducible defences）可使猎物在捕食者存在时提升存活几率，同时规避捕食者缺失时产生的不必要成本。诸多研究均表明，诱导防御的表达存在显著的个体间差异，然而该差异背后的驱动机制仍未得到充分阐释。脊椎动物捕食诱导型形态防御的经典案例，是鲫（Carassius carassius）的体高增加——这一特征可降低受张口限制型捕食者（gape-size limited predators）攻击的捕食风险。本研究发现，形态防御表达的个体间差异可与性别相关联。我们在存在捕食者的湖泊中观测到鲫的性别二态性：雌性个体的相对体高显著低于雄性，而在无捕食者的湖泊中并未出现该现象。当将来自无捕食者种群的鲫置于实验室环境下的模拟捕食风险（即白斑狗鱼（Esox lucius）存在/缺失条件）中时，我们发现雄性个体的防御表达量显著更高……