Using microalgae to alleviate the adverse effects of aquaculture pollutants, including metals, has recently gained much attention. In this context, bioaccumulation, hematological indices, oxidative and antioxidant responses, and histopathological alterations were investigated in Nile tilapia (Oreochromis niloticus) fed with either a control diet or diets containing Nannochloropsis oculata (N. oculata) after exposure to mercuric chloride in order to evaluate the role of this microalgae in protecting against mercury-induced toxicity. Fish exposed to HgCl₂ at a dose of ¼ LC₅₀ (0.3 mg/L) (Hg group) for 7-21 days exhibited a significant increase in total mercury concentration with a bioaccumulation pattern of liver>gills>muscle, and a significant decrease in all blood indices except mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), monocyte counts, and neutrophil counts. Malondialdehyde (MDA) levels were significantly increased in the Hg group at all time points relative to the control. Glutathione peroxidase (GPx) activity was significantly increased at days 14 and 21, while catalase (CAT) and GPx activities increased and decreased, respectively, at day 7 compared to the control. Additionally, lysozyme activity and immunoglobulin M (IgM) were significantly decreased in the Hg-exposed group. Severe histopathological alterations were evident in the liver, kidneys, and gills. However, supplementation with N. oculata at a low (5%, 50 g/kg feed) or high (10%, 100 g/kg feed) dose stabilized all parameters and reduced the severity of the histopathological alterations with the high N. oculata diet showing more prominent effects. These results suggest that feeding N. oculata protects Nile tilapia against mercuric chloride-induced toxicity.

利用微藻来减轻包括金属在内的水产养殖污染物的不利影响，最近受到了广泛关注。在此背景下，研究了尼罗罗非鱼（Oreochromis niloticus）的生物蓄积性、血液学指数、氧化和抗氧化反应以及组织病理学改变，这些罗非鱼在接触氯化汞后，用对照饮食或含Nannochloropsis oculata ( N. oculata ) 的饮食喂养，以便评估这种微藻在防止汞引起的毒性方面的作用。暴露于剂量为 ¼ LC _{50 的}HgCl _{2 的}鱼(0.3 mg/L) (Hg 组) 7-21 天，总汞浓度显着增加，生物蓄积模式为肝>鳃>肌肉，除平均红细胞体积 (MCV) 外，所有血液指标均显着下降，平均红细胞血红蛋白 (MCH)、单核细胞计数和中性粒细胞计数。与对照组相比，汞组的丙二醛 (MDA) 水平在所有时间点均显着增加。与对照相比，谷胱甘肽过氧化物酶 (GPx) 活性在第 14 天和第 21 天显着增加，而过氧化氢酶 (CAT) 和 GPx 活性在第 7 天分别增加和减少。此外，汞暴露组的溶菌酶活性和免疫球蛋白 M (IgM) 显着降低。在肝脏、肾脏和鳃中明显存在严重的组织病理学改变。然而，N. oculata以低（5%，50 g/kg 饲料）或高（10%，100 g/kg 饲料）剂量稳定所有参数并降低组织病理学改变的严重程度，而高N. oculata饮食表现出更突出效果。这些结果表明喂养N. oculata可以保护尼罗罗非鱼免受氯化汞诱导的毒性。