School of Life Sciences, Arizona State University, Tempe, AZ 85281, USA.
School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ 85281, USA.
Integr Comp Biol. 2021 Oct 4;61(3):1191-1201. doi: 10.1093/icb/icab122.
Anthropogenic activities often lead to alterations in the natural environment via multiple routes. Simultaneous occurrence of interacting environmental perturbations may influence animals via more complex pathways than when being exposed to environmental stressors discretely. In our study, we investigated the interactive effects of poor visual environment and exposure to an environmentally realistic concentration of a common contaminant on the behavior of larval zebrafish, Danio rerio. Specifically, we tested the sensory-motor behavior of zebrafish larvae by exposing them to low-light conditions and a low concentration of bisphenol-A (BPA) for 7 days postfertilization. We found that zebrafish exposed to both BPA and low-light conditions had significantly weaker response to a moving-visual cue. However, those exposed to only one of these treatments did not have altered response to visual cues. Since the response to a moving, visual cue involves locomotion, we also examined the distance they traveled as a proxy for activity level of individuals across treatments. However, the distance traveled by individuals did not significantly differ across treatments, suggesting that the differences in response are linked to visual sensory pathways. Here, we emphasize that the adverse effects of environmental stressors, particularly of those that occur at environmentally relevant concentrations, may emerge only when they co-occur with another environmental stressor. These findings highlight the need to incorporate multiple environmental stressors to comprehensively assess impacts that human activities have on behavioral strategies of animals.
人为活动通常通过多种途径导致自然环境的改变。同时发生的相互作用的环境干扰可能通过比单独暴露于环境胁迫更复杂的途径影响动物。在我们的研究中，我们研究了不良视觉环境和暴露于环境中常见污染物实际浓度的共同作用对斑马鱼幼虫（Danio rerio）行为的影响。具体来说，我们通过在受精后 7 天内将斑马鱼幼虫暴露于低光照条件和低浓度双酚 A（BPA）下来测试它们的感觉-运动行为。我们发现，同时暴露于 BPA 和低光照条件下的斑马鱼对移动视觉线索的反应明显较弱。然而，那些仅暴露于这些处理方法之一的斑马鱼对视觉线索没有改变的反应。由于对移动视觉线索的反应涉及到运动，我们还检查了它们作为个体在不同处理方法之间的活动水平的代理的行进距离。然而，个体的行进距离在不同的处理方法之间没有显著差异，这表明反应的差异与视觉感觉途径有关。在这里，我们强调指出，环境胁迫，特别是那些在环境相关浓度下发生的环境胁迫的不利影响，只有在它们与另一个环境胁迫同时发生时才会出现。这些发现强调了需要综合评估人为活动对动物行为策略的影响，需要将多种环境胁迫因素纳入其中。
