Ghousia Begum

In vivo toxicity of dimethoate on proteins and transaminases in the liver tissue of fresh water fish Clarias batrachus (Linn)

Environmental pollution due to extensive usage of the pesticides to enhance farm productivity and inexpensive control of vector-borne diseases without proper management has far reaclfing effect on the survival potential of aquatic animals. Some of these toxic chemicals may persist in the environment for long periods, often unchanged. These chemicals, apart from affecting the target pests also affects the nontarget organisms present in that media. Fish form one of the important nontarget organisms in any aquatic systems, and are one of the major sources of cheap protein for human beings in India. Results of controlled laboratory exposures of fishes to pesticides and related chemicals have revealed that liver is often the organ with lfighest pesticides concentration (Duke and Wilson 1971). Although more than 900 commercial pesticides are in general use, fewer than 30 have been examined for their adverse effects on fish liver ( Pimentel 1971; Gupta 1986 ). Therefore in the present investigation, the effect of commercial Dimethoate EC 30 % (O, O-dimethyl S (N - methylcarbamoylmethyl) Phosphorodithioate), and organophosphorus (OP) insecticide on the liver ofClarias batrachus (Linn) was studied. MATERIALS AND METHODS C. batrachus in the weight range of 35 - 40 g and length 20 - 22 cm were collected locally and acclimatized to laboratory conditions for 2 wk, fed with commercial balanced fish feed and starved for 1 d prior to the day of experimentation. The physicochemical characteristics of the laboratory water were in the tbllowing range: pH 7.3 - 7.5; dissolved oxygen 7.5 - 8 mg/L; temperature 27~ - 29~ hardness 98 - 100 mg/L as CaCO3; and alkalinity 85 - 90 mg/L as CaCO 3. The dimethoate EC 30% was obtained from the l,~cal market ( Rallis India Ltd., Bombay, India). The other 70% were the solvents and emulsifiers. The control fish were maintained with 0.1 mL/L alcohol as it was used for dissolving dimethoate. To determine the LCso value, ten fish per 10 L of water were exposed to six serial concentrations of dimethoate. The bioassay experiment of each concentration was repeated six times

Cypermethrin-induced biochemical perturbations in freshwater fish Clarias batrachus at sublethal exposure and after released into freshwater.

Cypermethrin-induced alterations in the fish, Clarias batrachus were studied. The fish were exposed to cypermethrin at a concentration of 0.07 mg/L for 10 days. After 10 days, fish were released into freshwater to observe the recovery response. At the end of 1, 5, and 10 days of exposure and after transfer into freshwater, different parameters were estimated in muscle and kidneys. Reduction in proteins was observed in both tissues, and recovery response was seen in muscle and kidneys. Free amino acid and ammonia content was enhanced in muscle and kidney for the 10 days. Transaminases (ALAT and AAT) and glutamate dehydrogenase activities were increased in both tissues for 10 days exposure span. Enzyme activities did not show much of the recovery.

Enzymes as Biomarkers of Cypermethrin Toxicity: Response of Clarias batrachus Tissues ATPase and Glycogen Phosphorylase as a Function of Exposure and Recovery at Sublethal Level

The present study was conducted to evaluate the sublethal effects of a synthetic pyrethroid, cypermethrin on ATPase, and glycogen phosphorylase in gill, kidney, liver, and muscle tissue of freshwater fish, Clarias batrachus (Linn) during exposure and cessation of exposure. Thirty-six fish were exposed to 1/3 of LC 50 concentration i, e. 0.07 mg/L cypermethrin for 10 days. After 10 days, 18 fish were transferred to freshwater and 10 days recovery response was observed. Thirty-six fish were kept as a control group. The effect of cypermethrin intoxication was studied on total, Mg+2, Na+-K+ ATPase, glycogen, and glycogen phosphorylase (a) and (ab) in various physiological tissues at the end of 1, 5, and 10 days of exposure and recovery period. Cypermethrin intoxication resulted in a significant inhibition in the activities of total, Mg+2, and Na+-K+ ATPase enzyme and glycogen content, whereas it caused a significant induction in the levels of glycogen phosphorylase (a). The activity level of glycogen phosphorylase (ab) showed mixed response. When exposed fish were released into freshwater, they were able to normalize the activities of ATPase enzyme in liver tissue whereas gill, kidney, and muscle tissues showed slight recovery. At the end of 10 days of recovery period, glycogen and glycogen phosphorylase activities in kidneys recover better than muscle. Therefore, the present study clearly suggests that ATPase and glycogen phosphorylase enzymes can be used as biomarkers of exposure to aquatic organisms under cypermethrin intoxication.

Carbofuran toxicity on total lipids and free fatty acids in air breathing fish during exposure and cessation of exposure--in vivo.

Clarias batrachus, fish were exposed to sublethalconcentration of commercial carbofuran for 144 hr. After 144 hrof exposure period, fish were transferred to fresh water and kept inthe same for 144 hr in order to study the effect of carbofuranafter cessation of intoxication. Total lipids and free fattyacids were determined in liver, muscle kidney and ovary at aninterval of 24, 72 and 144 hr during exposure and after therelease into toxicant free water. Total lipids increased in allthe tissues throughout the exposure period, followed by decreaseduring depuration period. The results showed an alteration infree fatty acid content in different tissues of the fish. Theelevated levels returned to almost control values after transferof fish into carbofuran free water.

Bioaccumulation and depuration of rogor in branchial tissue of clarias batrachus (Linn)

Bioaccumulation of technical rogor, (dimethoate, cygon) an organophosphorus insecticide in an air breathing fish, Clarias batrachus exposed to sublethal concentration (16.66 mg/L) was carried out during different periods of time interval. A parallel group of fish without insecticide served as control. Depuration studies on the fish were also carried out following cessation of exposure. Branchial tissue was isolated from both the groups and subjected to gas chromatography (GC) examination. Presence of dimethoate residue was confirmed by gas chromatography ‐ mass spectrometry (GC ‐ MS). Bioaccumulation of rogor in the gill tissue of fish increased from 24 hours (4.04 μg/g wet weight) to 48 hours (13.39 μg/g wet weight) and thereafter it decreased till 192 h. When the fish were released into freshwater, elimination of rogor was noticed. It was found that branchial tissue was devoid of rogor at 192 h following their release into freshwater.