We have a tendency to evaluated the impact of metal (Cd) on the structure and performance of the top excretory organ within the seafood Tambaqui (C. macropomum). Juveniles were exposed to zero.1 mg/L CdCl2 for thirty one days. Blood samples were examined mistreatment haematological tests and head excretory organ microscopic anatomy make up my mind by lightweight research. The concentration of Cd within the head Associate in Nursingd trunk kidneys was measured mistreatment an atomic absorption photometer. Cd made study of diseases of the tissues transformation within the head excretory organ, the foremost evident of those being: the thickening of the vein wall, a rise within the range of basophils/mast cells about to blood vessels and a severe depletion of haematopoietic precursors particularly the granulopoietic series. within the blood, a decrease within the total leucocytes and haemoprotein concentration was ascertained. Cd-exposed fish showed higher Cd concentrations within the trunk excretory organ than the top excretory organ. lastly, exposure to Cd affected precursor haematopoietic cells in C. macropomum.