Climate Change Induce the Toxicity of Black Sand Nanoparticles on Catfish (Clarias gariepinus) Using Hemato-Hepatological Biomarkers

This study aimed to explore the effects of heat stress and black sand acute exposure on the erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices. Catfish were subjected to black sand nanoparticles (6.4 g of nanoparticles black sand per kg of diet), thermal stress (32 degrees C), and a combined treatment involving both stressors over a period of 15 days. Catfish exposed to black sand nanoparticles and heat stress singly and/or in combination showed significantly lower red blood cells (RBCs) count, hemoglobin (Hb), platelets, white blood cells (WBCs) count, large lymphocytes, small lymphocytes, and monocytes. Antioxidant indices decreased in black sand NPs and heat stress combination compared to other groups. Notably, the combination of black sand nanoparticles and heat stress led to a substantial increase in the percentages of both RBCs alterations and nuclear abnormalities. Histological examinations of the liver revealed various features, including intracellular bleeding, cytoplasmic vacuolation, tissue deterioration, hepatocyte pyknotic nuclei, nuclear displacement, shrinkage, and accumulation of melanomacrophage cells. In conclusion, the study underscores that the effects of black sand nanoparticles on erythron profile, hematological and antioxidant parameters, as well as histological and histochemical indices, become more pronounced under elevated temperatures indicating the potential for synergistic effects between pollution and climate change. This holistic approach is crucial for developing more accurate forecasts of the complex interactions between environmental stressors and their implications for aquatic ecosystems.