Studies on the histopathological changes in selected tissues of fish Labeo rohita exposed to phenol.

Histopathological changes in vital tissues like gills, liver and kidney in the fish Labeo rohita exposed for 8 days to sublethal (5.2 mgl-1) and lethal concentration (25.09 mgl-1) of phenol were studied. The observed histopathological changes in the gills were epithelial hyperplasia with lamellar fusion, epithelial hypertrophy, edema, general necrosis, increased mucous production and degeneration of primary and secondary gill lamellae at sublethal (5.2 mg l-1) and degenerated primary and secondary gill lamellae, lamellar fusion and lamellar disorganization at lethal (25.09 mg l-1) concentration. In the liver, the changes include as: formation of number of vacuoles, enlargement of nuclei of some cells, enlarged sinusoids with numerous blood cells and atrophic areas at sublethal (5.2 mg l-1) concentration and nuclear and cytoplasmic degeneration and melanomacrophages aggregates at lethal (25.09 mg l-1) concentration. In case of kidney, the changes were: degeneration of proximal and distal convoluted tubule, vacuolation of renal interstitial tissue and deformation of the nuclear membrane of some cells at sublethal (5.2 mg l-1) and occlusion of tubular lumen, cloudy swelling degeneration and hyaline droplets degeneration at lethal (25.09 mg l-1) concentration.

Effects of alachlor on biochemical parameters of the freshwater fish, Channa punctatus (Bloch).

The fresh water fish Channa punctatus (Bloch) were exposed to lethal and sublethal concentrations of a chloroacetanilide herbicide Alachlor and its commercial formulation Lasso 50% Emulsifiable Concentrate EC to study the impacts on some biochemical parameters - the energy dependent sources: such as glycogen, total proteins and metabolic enzymes: Aspartate Amino Transferase (AAT), Alanine Amino Transferase (ALAT), Lactate Dehydrogenase (LDH), Deoxyribonucleic acid (DNA) and Ribonucleic Acid (RNA). The glycogen, total proteins, DNA, RNA were all decreased but the activity of the enzymes AAT, ALAT and LDH were all increased which is due to the toxic stress. The percentage decrease being more pronounced at lethal concentrations than at sublethal concentrations.

Studies on histopathological changes in the gill, liver and kidney of Channa punctatus (Bloch) exposed to Alachlor.

Freshwater fish, Channa punctatus was exposed to sublethal concentration of a chloroacetanilide herbicide alachlor technical grade and lasso 50% EC for a period of 10 days. The histopathological changes in the gill include: necrosis, vacuolar degeneration, fusion and atrophy of primary and secondary gill lamellae. The tissue damages like degeneration of cytoplasm in hepatocytes, atrophy, formation of vacuoles, rupture in blood vessels and disposition of hepatic cords are the histopathological changes observed in the liver. The changes in the kidney include: necrosis, swelling of renal tubules, cellular hypertrophy and granular cytoplasm.

Toxicity studies of butachlor to the freshwater fish Channa punctata (Bloch).

The toxicity studies were conducted on the fish Channa punctata (Bloch) by employing static and continuous flow through systems, for the toxicant butachlor (technical grade+) and its commercial formulation+ (machete 50% EC). The LC50 values are 297.89 ppb and 247.46 ppb for 24 hr and 48 hr in static for technical and 636.45 and 546.09 for machete. In continuous flow through the values are 270.05, 233.52 to the technical and 567.85 and 481.49 respectively for machete. The tissues show qualitative accumulation and were quantitatively analysed by gas liquid chromatography (GLC).

Effect of phenol on haematological components of Indian major carps Catla catla, Labeo rohita and Cirrhinus mrigala.

The effect of phenol on haematological components of Indian major carps, Catla catla, Labeo rohita and Cirrhinus mrigala were observed. After exposure to sublethal concentrations of 5.17 mg l(-1), 6.06 mg l(-1) and 6.99 mg l(-1), the number of red blood cells, haemoglobin content and packed cell volume all decreased but the glucose level increased. The order of decrease in the haematological components of the three fish is in the order of Catla catla > Labeo rohita > Cirrhinus mrigala.