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.近交衰退在胁迫环境中通常更为剧烈。然而，近交对种群抵御环境胁迫因子（如化学暴露）的脆弱性的影响程度，目前仍未明晰。本研究针对近交与内分泌干扰物（endocrine disrupting chemical）——杀菌剂克霉唑（clotrimazole）暴露的联合作用对斑马鱼（Danio rerio）的影响展开了探究。研究结果表明：尽管近交可对繁殖相关性状产生负面影响，但并非所有性状均受同等程度的影响；近交衰退往往仅在鱼类同时受到化学暴露胁迫时才显现出来。具体而言，近交且经化学暴露的斑马鱼胚胎存活率显著降低；近交雄性个体与非近交个体直接竞争时，其产仔数存在减少的趋势。血浆11-酮睾酮（11 keto-testosterone）作为关键雄性性激素，其水平表现出显著的近交衰退，且不受该杀菌剂暴露的影响。与之相反，近交或克霉唑暴露均未对产卵量产生显著影响。综上，本研究数据证实，胁迫可能加剧近交对关键繁殖性状的影响，尤其是与雄性适合度相关的性状。这一结论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。