The increasing contamination of water bodies with mercury raises concerns about its possible effects on aquatic organisms. The combined use of several biomarkers allows researchers to study the impact of a chemical at different levels of biological organization. In the present work, we determined the response of histological (gills and liver), somatic (condition factor and hepato-somatic index), and behavioral (predator–prey relationship, through the presentation of a computer-animated image) biomarkers in the native species Psalidodon eigenmanniorum exposed to 100 µg L⁻¹ of inorganic Hg (IHg) during 96 h. We also assessed whether there was a change in the biomarkers analyzed after 7 days in Hg-free water compared with those exposed to IHg. In exposed fish, IHg caused damage to the gills and liver tissues. The condition factor showed no difference between IHg-exposed organisms and control organisms, while the hepato-somatic index was lower in IHg-exposed fish. As for the behavioral analyses, it was observed that the presentation of a stimulus induced changes in the behavioral responses of fish exposed to IHg, which showed a heightened state of alertness with respect to control. On the other hand, after 7 days in Hg-free water, the organisms generally showed no changes in biomarkers compared with IHg-exposed fish. Our results contribute new data on IHg toxicity in a native species and provide information on the plasticity of damage to reverse itself. Furthermore, this work provides baseline information for environmental assessments in water bodies where mercury is present.

汞对水体的日益污染引起了人们对其可能对水生生物产生影响的担忧。几种生物标志物的联合使用使研究人员能够研究化学物质对不同生物组织水平的影响。在目前的工作中，我们确定了组织学（鳃和肝脏）、体细胞（条件因素和肝体指数）和行为（捕食者-猎物关系，通过呈现计算机动画图像）生物标志物在原生生物中的反应物种Psalidodon eigenmanniorum暴露于 100 µg L ^-196 小时内的无机汞 (IHg)。我们还评估了在无汞水中 7 天后分析的生物标志物与暴露于 IHg 的生物标志物相比是否发生了变化。在暴露的鱼中，IHg 对鳃和肝组织造成损害。条件因子显示 IHg 暴露的生物与对照生物之间没有差异，而 IHg 暴露的鱼的肝体指数较低。至于行为分析，观察到刺激的呈现会导致暴露于 IHg 的鱼的行为反应发生变化，这显示出对控制的高度警觉状态。另一方面，在无汞水中 7 天后，与接触 IHg 的鱼相比，这些生物体的生物标志物通常没有变化。我们的研究结果提供了有关 IHg 对本地物种的毒性的新数据，并提供了有关损害可塑性的信息以逆转自身。此外，这项工作为存在汞的水体中的环境评估提供了基线信息。