Sacrificial males: the potential role of copulation and predation in contributing to copepod sex-skewed ratios

Predation is thought to play a selective role in the emergence of behavioural traits in prey. Differences in behaviour between prey demographics may, therefore, be driven by predation with select components of the population being less vulnerable to predators. While under controlled conditions prey demography has been shown to have consequences for predation success, investigations linking these implications to natural prey population demographics are scarce. Here we assess predator-prey dynamics between notonectid predators (backswimmers) and Lovenula raynerae (Copepoda), key faunal groups in temperate ephemeral pond ecosystems. Using a combination of field and experimental approaches we test for the development and mechanism of predation-induced sex-skewed ratios. A natural population of L. raynerae was tracked over time in relation to their predator (notonectid) and prey (Cladocera) numbers. In the laboratory, L. raynerae sex ratios were also assessed over time but in the absence of ...捕食被认为在猎物行为性状的演化起源中发挥选择作用。因此，猎物种群间的行为差异可能由捕食作用驱动：种群中的特定亚群对捕食者的易感性更低。尽管在受控条件下，猎物种群结构已被证实会影响捕食成功率，但将此类影响与自然猎物种群统计特征相关联的研究仍较为匮乏。本研究针对温带临时性池塘生态系统（ephemeral pond ecosystems）中的两类关键动物类群——仰泳蝽科捕食者（backswimmers）与桡足纲（Copepoda）的Lovenula raynerae，评估二者间的捕食者-猎物动态（predator-prey dynamics）关系。本研究结合野外调查与实验手段，探究捕食诱导的性比偏倚（sex-skewed ratios）现象的发生过程与内在机制。研究团队对自然种群中的L. raynerae进行长期监测，同步记录其捕食者（仰泳蝽科）与猎物（枝角类（Cladocera））的种群数量变化。在实验室条件下，本研究同样对L. raynerae的性比随时间的变化进行了评估，但实验中未添加……