摘要：Environmental pollutants such as pesticides, industrial wastes and other organic wastes pose serious risks to many aquatic organisms. Accordingly a great deal of previous research has characterized physiological mechanisms of toxicity in animals exposed to contaminants. In contrast, effects of aquatic contaminants on fish pathology and physico-chemical characteristics of aquatic system are less frequently studied. To investigate present position of the dam water physico-chemical characteristics and histopathological changes in fish was undertaken. Analysis exhibited richness in nitrogen, phosphates, in addition to high value of total dissolved solids, total alkalinity, DO, BOD and organic matter . The histological damage caused to the fish Glossogobius giuris by various aquatic pollutants present in polluted water body. A microscopic study exhibits the Swelling Gill Lamellae (SGL) and fusion of secondary lamellae (FL) of gill filaments and oedematous separation of basement membrane from epithelial lining of the Secondary Lamellae (SL) was also noticed. Cellular hypertrophy followed by vacuolization in Thyroid Follicles (TF), irregular pluripotent haemoblasts (hae) in haematopoietic tissue and vacuolated erythrocytes (RBCs), neutrophils and monocytes in the peripheral blood. The results obtained suggests that the gills,thyroid,haematopoietic tissue and peripheral blood cells were structurally altered in polluted water body fishes. Such alterations could affect vital physiological functions such as respiration, osmotic and ionic regulation of the gills, storage and secretion in thyroid follicles, haemopoesis of the kidney and oxygen carrying capacity, haemoglobin content in erythrocytes and loss of immune mechanism, phagocytosis in leucocytes, which inturn could ultimately affect the survival and growth of G. giuris . Thus all possible remedial measures should be adopted to prevent the occurrence of contamination in the aquatic environment.
