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.

Acute toxicity of nuvan®, an organophosphate to freshwater fish Ctenopharyngodon idella and its effect on oxygen consumption.

The acute toxicity of Nuvan to the grass carp Ctenopharyngodon idella was determined using static and continuous flow through system for 24, 48, 72 and 96 hr. The median lethal concentration (LC50) values were 13.1, 10.9, 9.8 and 6.5 mg l-1 respectively in static system and 10.7, 9.5, 8.0 and 7.5 mg l-1 respectively in continuous flow through system. A reduction in oxygen consumption is observed when the fish is exposed to the toxicant and the mortality is due to effect of metabolism of energy synthesis.

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.

Effects of ammonia, nitrite and nitrate on hemoglobin content and oxygen consumption of freshwater fish, Cyprinus carpio (Linnaeus).

Lethal effects of nitrogenous compounds ammonia, nitrite and nitrate on freshwater fish Cyprinus carpio were studied and the static LC50 values obtained for these 3 toxicants for 24 hr were 0.80 ppb, 171.36 ppm; 1075.10 ppm and continuous flowthrough LC50 values for 24 hr were 0.72 ppb, 154.31 ppm; 967.63 ppm respectively. The fish were exposed to lethal concentrations to study the changes in hematological parameters and the rate of oxygen consumption. During the period of exposure general decline in the content of hemoglobin was observed. Methemoglobin content increased in case of nitrite exposure consequently the hemoglobin levels decreased drastically. It is also observed that rate of oxygen consumption decreased progressively with the increase of toxicant concentration and duration of the exposure.

Biochemical changes induced by chlorpyrifos, an organophosphate compound in sublethal concentrations to the freshwater fish Catla catla, Labeo rohita and Cirrhinus mrigala.

Freshwater fishes, Catla catla, Labeo rohita and Cirrhinus mrigala were exposed to sublethal concentration of the pesticide chlorpyrifos an organophosphate pesticide. Biochemical changes in total glycogen, total proteins, lactate dehydrogenase (LDH), alanine amino transferase (ALAT) and aspartate amino transferase (AAT) and nucleic acids, Deoxy and ribose, were estimated in the tissues of fishes exposed to the toxicant chlorpyrifos technical grade. The decrease in total glycogen and proteins over control and increase in selected enzymes, LDH, AAT, ALAT, DNA and RNA values were observed in the three fishes exposed to the toxicant.

The effect of Chlorpyrifos, an organophosphate in acetyl cholinesterase activity in freshwater fishes.

The freshwater fish Catla catla, Labeo rohita and Cirrhinus mrigala are exposed to the toxicant chlorpyrifos, an organo phosphate commonly used in agriculture as well as in aquaculture. The effect was studied on the enzyme acetyl cholinesterase activity which was inhibited in the selected tissues of the fish. In different tissues and in brain, the maximum inhibition was observed.

Effect of fenvalerate technical grade on acetyl cholinesterase activity in Indian bullfrog Haplobatrachus tigerinus (Daudin).

Indian bullfrog Haplobatrachus tigerinus (Daudin) was exposed to sublethal dose (1/3 of LC50 I.E. 1.166 mg/kg) of fenvalerate technical grade and the effect was studied on the specific activity of acetyl cholinesterase in the different tissues of frog viz., brain, muscle, liver, kidney and testis at different time periods viz., 3,6, 12, 24, 48 and 72 hours. The inhibition of specific activity of acetyl cholinesterase was in the order of kidney > brain > muscle > liver > testis. A significant inhibition was noticed in kidney at 12 hours (-64.33%) and no effect was noticed at 3 hours in testis (+0.67%). The AChE activity was inhibited in first three hours of administration of fenvalerate in all the tissue tested. The inhibition continued upto 6 hours or 2 hours in different tissue but the recovery was started by 24 hours and almost completed by 72 hours.

Bioaccumulation of fenvalerate technical grade in different organs of the frog Haplobatrachus tigerinus (Daudin).

Bioaccumulation studies of fenvalerate were conducted on Indian bullfrog Haplobatrachus tigrinus (Daudin) after exposure to sublethal intraperitoneal dose of technical grade fenvalerate (1/3 LD50 i.e. 116.66 microg/kg body weight) at 3, 6, 12, 24, 48 and 72 hours schedule. The tissues viz., muscle, liver, kidney, testis, brain, and whole body accumulation was analysed for residue estimations. In all the tissues, analysed maximum residue was recovered in the initial stages of exposure (3 and 6 hours). However, in brain the residues remained up to 72 hours. In the whole body, analysis after 3 hours of exposure 78.65% residue was recovered and by the time 72 hours passed only, 9.4% residue was recovered. The decline in residue levels along with the period of exposure indicates the fast acting nature of fenvalerate and metabolites.

Studies of some biochemical changes in the tissues of Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton) exposed to NH3-N, NO2-N and NO3-N.

Biochemical changes, total proteins, glycogen, aspartate and alanine (AAT and ALAT) amino transferases were studied with exposure of sublethal concentrations of NH3-N, NO2-N and NO3-N to the freshwater fish Catla catla (Hamilton), Labeo rohita (Hamilton) and Cirrhinus mrigala (Hamilton). Depletion in the food reserves and enzyme activity was observed in all the three fish species exposed to these toxicants. Hence, the concentrations of NH3, NO2 and NO3 in water need to be monitored in water quality in aquaculture practices.

The toxicity of ammonia, nitrite and nitrate to the fish, Catla catla (Hamilton).

The acute toxicity of unionized ammonia; nitrite and nitrate to the Indian major carp Catla catla (Hamilton) was determined using static and continuous flow through systems for 24 hours. The median lethal concentration (LC50) values for 24 h of ammonia (NH3-N), nitrite (NO2-N) and nitrate (NO3-N) were 0.045 mg/l, 120.84 mg/l and 1565.43 mg/l in static test respectively and were 0.036 mg/l, 117.43 mg/l and 1484.08 mg/l in continuous flow through test respectively.

Toxicity and residue studies of fenvalerate to some selected freshwater fishes.

The toxicity test of fenvalerate were conducted to fresh water fishes Labeo rohita (Hamilton), Catla catla (Hamilton), Cirrhinus mrigala (Hamilton), Aplocheilus punchex (Hamilton) and Ctenopharygodon idellus (Valenciennes). The static and continuous flow through tests were employed to determine the lethal concentration (LC50) for 24h, 48h and 96h to the test fish. It was observed that Cirrhinus mrigala is more sensitive to this pesticide followed by Applochielus punchex, Lebeo rohita, Catla catla and Ctenopharyngodon idellus. The residue analysis for qualitative confirmation was done by thin layer chromatography (TLC) to assess the deposition of pesticide in different tissues of fishes. The quantitative study of accumulation in the whole body tissue was done by Gas liquid chromatography (GLC). The quantitative residues confirm the toxic action.