Data from: Interactive effects of inbreeding and endocrine disruption on reproduction in a model laboratory fish

Inbreeding depression is expected to be more severe in stressful environments. However, the extent to which inbreeding affects the vulnerability of populations to environmental stressors, such as chemical exposure, remains unresolved. Here we report on the combined impacts of inbreeding and exposure to an endocrine disrupting chemical (the fungicide, clotrimazole) on zebrafish (Danio rerio). We show that whilst inbreeding can negatively affect reproductive traits, not all traits are affected equally. Inbreeding depression frequently only became apparent when fish were additionally stressed by chemical exposure. Embryo viability was significantly reduced in inbred exposed fish and there was a tendency for inbred males to sire fewer offspring when in direct competition with outbred individuals. Levels of plasma 11 keto-testosterone, a key male sex hormone, showed substantial inbreeding depression that was unaffected by addition of the fungicide. In contrast, there was no effect of inbreeding or clotrimazole exposure on egg production. Overall, our data provide evidence that stress may amplify the effects of inbreeding on key reproductive traits, particularly those associated with male fitness. This may have important implications when considering the consequences of exposure to chemical pollutants on the fitness of wild populations.近亲繁殖衰退（inbreeding depression）在胁迫环境中往往更为严重。然而，近亲繁殖究竟会在多大程度上影响种群对环境胁迫因子（如化学暴露）的脆弱性，目前仍未得到明确解答。本研究探讨了近亲繁殖与内分泌干扰化学物（endocrine disrupting chemical）——杀菌剂克霉唑（clotrimazole）——暴露的联合效应对斑马鱼（Danio rerio）的影响。研究结果表明，尽管近亲繁殖会对繁殖相关性状产生负面影响，但并非所有性状的受影响程度均一致；近亲繁殖衰退往往仅在鱼类同时受到化学暴露胁迫时才会显现。经近亲繁殖且暴露于化学物的斑马鱼，其胚胎存活率显著降低；同时，近亲繁殖雄性个体在与非近亲繁殖个体直接竞争时，存在繁殖后代数量更少的趋势。血浆中11-酮基睾酮（11 keto-testosterone，一种关键的雄性性激素）的水平出现了显著的近亲繁殖衰退，且该效应不受杀菌剂添加的影响。与之相反，近亲繁殖或克霉唑暴露均未对产卵量产生显著影响。总体而言，本研究数据证实，胁迫可能会放大近亲繁殖对关键繁殖性状的影响，尤其是与雄性适合度相关的性状。这一发现对于评估化学污染物暴露对野生种群适合度的影响具有重要意义。