Abstract：
This study investigates the effects of glyphosate-based herbicide (GLY) and pure emamectin benzoate (EB) insecticide on the brackish copepod Pseudodiaptomus annandalei. The 96h median lethal concentration (96 h LC50) was higher in the GLY exposure (male: 3420.96 ± 394.67 μg/L; female: 3093.46 ± 240.67 μg/L) than in the EB (male: 79.10 ± 7.30 μg/L; female: 6.38 ± 0.72 μg/L). Based on the result of 96h LC50, we further examined the effects of GLY and EB exposures at sub-lethal concentrations on the naupliar production of P. annandalei. Subsequently, a multigenerational experiment was conducted to assess the long-term impact of GLY and EB at concentrations 375 μg/L, and 0.025 μg/L respectively determined by sub-lethal exposure testing. During four consecutive generations, population growth, clutch size, prosome length and width, and sex ratio were measured. The copepods exposed to GLY and EB showed lower population growth but higher clutch size than the control group in most generations. Gene expression analysis indicated that GLY and EB exposures resulted in the downregulation of reproduction-related (vitellogenin) and growth-related (myosin heavy chain) genes, whereas a stress-related gene (heat shock protein 70) was upregulated after multigenerational exposure. The results of the toxicity test after post-multigenerational exposure indicated that the long-term GLY-exposed P. annandalei displayed greater vulnerability towards GLY toxicity compared to newly-exposed individuals. Whereas, the tolerance of EB was significantly higher in the long-term exposed copepod than in newly-exposed individuals. This suggests that P. annandalei might have greater adaptability towards EB toxicity than towards GLY toxicity. This study reports for the first time the impacts of common pesticides on the copepod P. annandalei, which have implications for environmental risk assessment and contributes to a better understanding of copepod physiological responses towards pesticide contaminations.
摘要：
这项研究调查了基于草甘膦的除草剂（GLY）和纯emamectin苯甲酸酯（EB）杀虫剂对微咸co足类拟足动物的影响。GLY暴露（男性：3420.96±394.67μg/L；女性：3093.46±240.67μg/L）的96h中位致死浓度（96hLC50）高于EB（男性：79.10±7.30μg/L；女性：6.38±0.72μg/L）。根据96hLC50的结果，我们进一步研究了亚致死浓度下GLY和EB暴露对无子幼体产生的影响。随后，进行了多代实验，以评估GLY和EB在375μg/L浓度下的长期影响，和0.025μg/L分别通过亚致死暴露测试确定。在连续的四代中，人口增长,离合器尺寸，突起的长度和宽度，测量性别比例。在大多数世代中，暴露于GLY和EB的co足类动物的种群增长率较低，但离合器大小高于对照组和对照组。基因表达分析表明，GLY和EB暴露导致生殖相关（卵黄蛋白）和生长相关（肌球蛋白重链）基因下调，而应激相关基因（热休克蛋白70）在多代暴露后上调。多代后暴露后的毒性测试结果表明，与新暴露的个体相比，长期暴露于GLY的ANNandalei对GLY毒性表现出更大的脆弱性。然而,长期暴露的co足动物对EB的耐受性明显高于新暴露的个体。这表明，与对GLY毒性相比，甘草对EB毒性可能具有更大的适应性。本研究首次报道了常见农药对co足类的影响。这对环境风险评估具有影响，并有助于更好地了解co足类对农药污染的生理反应。
