Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Zagazig University, PO Box 44511, Zagazig, Sharkia, Egypt.
Department of Aquatic Animal Medicine, Faculty of Veterinary Medicine, Mansoura University, P.O. Box 35516, Mansoura, Dakahlia, Egypt.
Aquat Toxicol. 2023 Aug;261:106630. doi: 10.1016/j.aquatox.2023.106630. Epub 2023 Jul 2.
An acute exposure study of mancozeb (MAZ) fungicide was applied on Oreochromis niloticus for 96-h duration. Three hundred fish (20.50 ± 1.60 g) were assigned into six groups (50 fish/ group; 10 fish/replicate) and exposed to different six concentrations (0, 4, 8, 12, 16, and 20 mg L) of MAZ for 96-h. The Probit analysis program was used to compute the 96-h lethal concentration 50 (96-h LC) of MAZ. During the exposure duration, the fish's behavior, clinical symptoms, and mortalities were recorded daily. After the exposure period was ended, the hematological, biochemical, immunological, and oxidant/antioxidant parameters were evaluated. The results of this study recorded the 96-h LC of MAZ for O. niloticus to be 11.49 mg L. Acute MAZ exposure badly affected the fish's behavior in the form of increased the breath gasping and swimming activity with aggressive mode. The exposed fish showed excessive body hemorrhages and fin rot. The survival rate of the exposed fish to MAZ was 100, 80, 66, 50, 38, and 30% in 0, 4, 8, 12, 16, and 20 mg L MAZ, respectively. The hematological indices (red blood cell count, hemoglobin, packed cell volume%, and white blood cell count) were significantly decreased by increasing the MAZ exposure concentration (8-20 mg L). The acetylcholine esterase activity and immune indices (lysozyme, nitric oxide, immunoglobulin M, complement 3) were decreased by MAZ exposure (4-20 mg L). Acute MAZ exposure induced hepato-renal dysfunction and elevated stress-related parameter (cortisol) by increasing the MAZ concentration. A significant reduction in the antioxidant parameters (total antioxidant activity, catalase, and superoxide dismutase) with increasing the lipid peroxidation marker (malondialdehyde) was noticed by acute MAZ exposure (4 -20 mg L) in O. niloticus. Based on these outcomes, the MAZ exposure induced toxicity to the fish evident in changes in fish behavior, neurological activity, hepato-renal functioning, and immune-antioxidant responses which suggest physiological disruption.
曼克菌（MAZ）杀菌剂的急性暴露研究在奥利亚罗非鱼身上进行了 96 小时。将 300 条鱼（20.50±1.60g）分为六组（每组 50 条鱼；每组 10 条鱼），并暴露于不同的六个浓度（0、4、8、12、16 和 20mg L）的 MAZ 中 96 小时。使用概率单位分析程序计算 MAZ 的 96 小时半致死浓度（96-h LC）。在暴露期间，每天记录鱼的行为、临床症状和死亡率。暴露期结束后，评估血液学、生化、免疫学和氧化/抗氧化参数。这项研究的结果记录了奥利亚罗非鱼的 MAZ 96-h LC 为 11.49mg L。急性 MAZ 暴露严重影响了鱼的行为，表现为呼吸急促和游泳活动增加，呈攻击模式。暴露的鱼表现出过度的身体出血和鳍腐烂。暴露于 MAZ 的鱼的存活率分别为 0、4、8、12、16 和 20mg L MAZ 中的 100%、80%、66%、50%、38%和 30%。血液学指标（红细胞计数、血红蛋白、红细胞压积%和白细胞计数）随着 MAZ 暴露浓度（8-20mg L）的增加而显著降低。乙酰胆碱酯酶活性和免疫指标（溶菌酶、一氧化氮、免疫球蛋白 M、补体 3）随着 MAZ 暴露（4-20mg L）而降低。急性 MAZ 暴露通过增加 MAZ 浓度诱导肝肾功能障碍和应激相关参数（皮质醇）升高。在奥利亚罗非鱼中，随着脂质过氧化标志物（丙二醛）的增加，抗氧化参数（总抗氧化活性、过氧化氢酶和超氧化物歧化酶）显著降低，同时注意到急性 MAZ 暴露（4-20mg L）引起的氧化应激。基于这些结果，MAZ 暴露对鱼类的毒性表现为鱼类行为、神经活动、肝肾功能和免疫抗氧化反应的变化，表明生理功能受到破坏。
