EFFECT OF THE NITRATE FERTILIZER UREA ON THE ULTRASTRUCTURAL CHANGES IN THE GILL OF FRESHWATER FISH CATLA

Ultrastructural study of the gill of Catla catla on exposure to 10% LC 50 sublethal concentration of nitrate fertilizer urea was carried out. Hypertrophy and hyperplasia of the lamellar cells in combination with epithelial lifting and edema were noticed. Necrosis of pillar system with lamella resulted in blood congestion and even an aneurism. Hyper secretion of mucous on the epithelium is to protect against environmental alteration was also determined. Infiltrated macrophages and leucocytes in the lamellar tissue were observed which was a compensatory repair response to tissue damages. Apoptotic condition of the cell is evident by clumping of chromatin, swelling of nucleus and mitochondria

Toxic Effect of Cadmium on the Electrophoretic Protein Patterns of Gill and Muscle of Oreochromis mossambicus

The present study was carried out to determine the sub lethal toxic effects of the heavy metal cadmium on the electrophoretic protein fractions of gill and muscle tissues of Oreochromis mossambicus. Fishes were exposed to 10% sub lethal concentration (96 h LC50) of cadmium for a period of 10 days. The protein fractions in the muscle of experimental fishes were found to be increased (twelve fractions) with respect to controls (eight fractions). The numbers of protein fractions in the gills of test fishes were found to be lesser than the control fishes. The results of the present study prove that cadmium affects the protein fractions in the tissues of fishes