Microplastics (MPs, <5 mm) have been frequently detected in aquatic ecosystems, representing both health and ecological concerns. However data about the combined effects of MPs and other contaminants is still limited. This study aimed to evaluate the impact of MPs and the heavy metal copper (Cu) on zebrafish (Danio rerio) larvae development and behavior. Zebrafish embryos were subchronically exposed to MPs (2 mg/L), two sub-lethal concentrations of Cu (60 and 125 µg/L) and binary mixtures of MPs and Cu using the same concentrations, from 2-h post fertilization until 14 days post fertilization. Lethal and sub-lethal responses (mortality, hatching, body length) were evaluated during the embryogenesis period, and locomotor, avoidance, anxiety and shoaling behaviors, and acetylcholinesterase (AChE) activity were measured at 14 dpf. The results showed that survival of larvae was reduced in groups exposed to MPs, Cu and Cu+MPs. Regarding the behavioral patterns, the higher Cu concentration and mixtures decreased significantly the mean speed, the total distance traveled and the absolute turn angle, demonstrating an adverse effect on swimming competence of zebrafish larvae. Exposure to MPs and Cu, alone or combined, also affected avoidance behavior of zebrafish, with larvae not reacting to the aversive stimulus. There was a significant inhibition of AChE activity in larvae exposed to all experimental groups, compared to the control group. Moreover, a higher inhibition of AChE was noticed in larvae exposed to MPs and both Cu+MPs groups, comparatively to the Cu alone groups. Our findings demonstrate the adverse effects of MPs, alone or co-exposed with Cu, on fish early life stages behavior. This study highlights that MPs and heavy metals may have significant impacts on fish population fitness by disrupting locomotor and avoidance behaviors.

在水生生态系统中经常检测到微塑料（MPs，<5 mm），代表了健康和生态问题。但是，有关MP和其他污染物的综合作用的数据仍然有限。这项研究旨在评估MP和重金属铜（Cu）对斑马鱼（Danio rerio）幼虫的发育和行为。从受精后2小时到14天，将斑马鱼胚胎连续暴露于MPs（2 mg / L），两种亚致死浓度的Cu（60和125 µg / L）以及MPs和Cu的二元混合物（使用相同浓度）受精后。在胚胎发生期间评估致死和亚致死反应（死亡率，孵化率，体长），并在14 dpf时测量运动，回避，焦虑和浅滩行为以及乙酰胆碱酯酶（AChE）活性。结果表明，暴露于MPs，Cu和Cu + MPs的组幼虫的存活率降低。就行为方式而言，较高的Cu浓度和混合物会显着降低平均速度，总行进距离和绝对转角，证明对斑马鱼幼虫的游泳能力有不利影响。单独或组合暴露于MP和Cu也会影响斑马鱼的回避行为，幼虫对厌恶刺激没有反应。与对照组相比，暴露于所有实验组的幼虫对AChE活性都有明显的抑制作用。此外，与单独使用Cu组相比，在暴露于MPs和两个Cu + MPs组的幼虫中，对AChE的抑制作用更高。我们的发现证明了MP单独或与Cu共同暴露对鱼类生命早期行为的不利影响。这项研究强调，MP和重金属可能通过破坏运动和回避行为而对鱼类种群的适应性产生重大影响。幼虫对厌恶刺激没有反应。与对照组相比，暴露于所有实验组的幼虫对AChE活性都有明显的抑制作用。此外，与单独使用Cu组相比，在暴露于MPs和两个Cu + MPs组的幼虫中，对AChE的抑制作用更高。我们的发现证明了MP单独或与Cu共同暴露对鱼类生命早期行为的不利影响。这项研究强调，MP和重金属可能通过破坏运动和回避行为而对鱼类种群的适应性产生重大影响。幼虫对厌恶刺激没有反应。与对照组相比，暴露于所有实验组的幼虫对AChE活性都有明显的抑制作用。此外，与单独使用Cu组相比，在暴露于MPs和两个Cu + MPs组的幼虫中，对AChE的抑制作用更高。我们的发现证明了MP单独或与Cu共同暴露对鱼类生命早期行为的不利影响。这项研究强调，MP和重金属可能通过破坏运动和回避行为而对鱼类种群的适应性产生重大影响。相对于单独的铜基团。我们的发现证明了MP单独或与Cu共同暴露对鱼类生命早期行为的不利影响。这项研究强调，MP和重金属可能通过破坏运动和回避行为而对鱼类种群的适应性产生重大影响。相对于单独的铜基团。我们的发现证明了MP单独或与Cu共同暴露对鱼类生命早期行为的不利影响。这项研究强调，MP和重金属可能通过破坏运动和回避行为而对鱼类种群的适应性产生重大影响。