Acute effects of malathion 57 EC pesticides on the histology, and blood cell structure of Silver barb (Barbonymus gonionotus) in the South-west region of Bangladesh

Pesticides used in agriculture that wash off have a detrimental effect on freshwater fish in Bangladesh. The purpose of this research is to assess the effects of the organophosphate insecticide Malathion 57 EC on the silver barb (Barbonymus gonionotus). The effects of Malathion 57 EC at dosages of 0.001 and 0.005 ppm, respectively, were assessed using a histological bio-assay of the gill, liver, kidney, and RBC count of B. gonionotus. For B. gonionotus, the LC50 value of Malathion 57 EC was estimated to be 0.08 ppm. The notable alterations included gill clubbing, missing gill lamellae, hyperplasia, nuclear hypertrophy, vacuolation, glomerular enlargement, increasing the width of renal tubules, bleeding, necrosis, and pyknosis were found in the histological analysis. Large lymphocytes, dead cells, tear-shaped cells, a fusion of cells, binucleated cells, ghost cells, senile cells, and irregular cell shapes were among the abnormalities detected in peripheral nuclear erythrocytes. In B. gonionotus, the RBC count was considerably lower (P<0.01) at lower pesticide doses compared to higher ones. The outcome of the study shows that the organophosphorus pesticide has a negative impact on the histology and haematology of various organs in B. gonionotus. Res. Agric. Livest. Fish. Vol. 10, No. 2, August 2023: 207-218