Changes in the Leucocyte and Serum Biochemistry in Clarias gariepinus (Burchel) Exposed to Sublethal Lead Choride

Clarias gariepinus fingerlings were chronically exposed to sublethal concentrations of lead ( 0.00; 0.10 and 0.40 mg/L) as lead chloride for twenty eight days in the laboratory. The changes in the leucocytes and serum biochemical parameters (glucose, protein and total cholesterol) of the fish were determined every seven days for 28 days in a renewable static bioassay system. At the end of the study, these parameters were significantly (p < 0.05) elevated in the treatment groups when compared with the control. There was pronounced leucocytosis in the lead-exposed fish when compared with the control. The lymphocytes and the basophils were the most dominant agranulocyte and granulocytes, respectively. The magnitude of increase was influenced by both duration of exposure and concentration. The fish exposed to lead were significantly (p<0.05) hyperglycaemic and hypercholesteremic. The serum protein concentration was also significantly (p< 0.05) increased in the treatment groups when compared with the control. These changes are indications of stress imposed on the fish by lead and could be used as indices of lead poisoning. Keywords: Clarias, lead, hyperglycaemia, cholesterol, protein, leucocyt

Toxic, physiological, histomorphological, growth performance and antiparasitic effects of copper sulphate in fish aquaculture.

This paper provides the current state of knowledge available from the literature regarding the use of copper sulphate (CuSO4) in culture of freshwater and marine fish as related to toxicity, growth performance, physiology immunity, histomorphology and antiparasitic treatment. From this review, I have assessed and discussed all of these factors, as well as the potential strategies available for use in fish farming. Acute toxicity (96h-LD50) to CuSO4 varies widely among fish species (0.001?730 mg/L) depending on various water quality factors, and many fish species are sensitive to concentrations near those required for controlling and treating parasite infections. Acute exposure to CuSO4 may lead to mortality while sublethal exposure in different organism causes changes in feeding and swimming behaviour, growth performance, histomorphology of gills, liver, kidney, and spleen, hematology, blood biochemistry, the antioxidant defense system, and oxygen consumption. After exposure to copper sulphate, copper ions often accumulate in the gills, liver, kidney and spleen, and in the gills provokes changes in mucus and chloride cells, hyperplasia and/or hypertrophy of primary and/or secondary lamellae, edema of the gill epithelium, and lamellar fusion. Long and short-term exposure to copper sulphate may negatively affect the body growth of fish exposed, and control and treat ectoparasite infections that are discussed here. Copper sulphate may be a chemotherapeutic for controlling and treating ectoparasites in farmed fish because of its effectiveness and low cost

Cd-Induced Responses in Plasma Ionic Regulation and Oxidative Stress in Rainbow Trout (\u3cem\u3eO. mykiss\u3c/em\u3e) or Lake Whitefish (\u3cem\u3eC. clupeaformis\u3c/em\u3e) During Chronic Waterborne Exposure

During chronic exposure to Cd or other metals, freshwater fish generally undergo physiological changes that results in acclimation, following a phase of damage and subsequent repair. The mechanisms associated with deleterious cellular effects induced by Cd throughout long-term exposures are less understood than those of acute toxicity, and may relate to an over-production of reactive oxygen species. The objectives of the present study were to examine the changes in, and relationship between, tissue-specific oxidative damage and antioxidant response, as well as plasma ionic regulation and tissue accumulation, in two freshwater salmonids throughout chronic Cd exposure. Rainbow trout (O. mykiss) or lake whitefish (C. clupeaformis) were exposed to either 0 (control), 0.8 or 2.0 μg Cd/L in moderately hard water (140 mg CaCO3/L) for one month, and gills, liver, kidney and plasma were sampled throughout exposure. Measured responses included plasma Ca2+ and Na+, as well as total tissue Cd burden and indicators of oxidative stress (lipid peroxidation, protein damage and enzymatic antioxidant defense (as catalase activity)) in tissues. Fish of either species experienced initial disruptions in plasma ion levels and/or mortality, which were associated with elevated Cd burdens in the gills. Exposure to sublethal Cd was sufficient to cause early oxidative lipid and/or protein damage in the liver and kidney, and subsequent recovery may relate to the elevated and sustained CAT response in these tissues, in addition to other cellular defenses. Long-term lipid peroxidation was found only in the gills of exposed rainbow trout, suggesting that the antioxidant capacities and/or detoxification mechanisms of the gills may be different than those in other tissues or of lake whitefish. Overall, this study demonstrates that the degree and pattern of oxidative damage and enzymatic antioxidant defense induced by Cd during chronic waterborne exposure varies amongst tissues and species

Hormonal responses of the fish, Cyprinus carpio, to environmental lead exposure

The present study reports the acute and sublethal toxicity of lead nitrate on plasma cortisol and prolactin level of a freshwater fish, Cyprinus carpio. The median lethal concentration of lead nitrate to fish for 24 h was found to be 4.10 ppm. 1/10th of the LC50 concentration of the lead nitrate (0.41 ppm) was taken for sublethal concentration. During acute and sublethal treatment the plasma cortisol level increased throughout the study period showing a direct relationship with exposure period. Similarly, plasma prolactin level was increased during acute treatment. However during sublethal treatment plasma prolactin level was increased up to 14th day and then declined. The significant increase of plasma cortisol level might have resulted from the release of cortisol from the interrenal tissue as a mechanism of coping up with stress or impaired immune function. The elevated level of plasma prolactin may be a step to reestablish ionic equilibrium due to the disturbances caused by the metal. Whereas the decline in plasma prolactin level indicate the destruction of prolactin cells due to metal toxicity. The alterations of the hormonal levels may be used as a potential biomarker and also can establish the ability of endocrine tissues to respond to their appropriate releasing factors

Heavy metal biomarker: fish behavior, cellular alteration, enzymatic reaction and proteomics approaches

Due to the latest industrial development, many dangerous chemicals have been released directly or indirectly which resulted in the polluted water bodies. Water rehabilitation is an alternative way to restore the quality of water, followed by the environmental management to control the waste discharge to ensure the balance of the degradation rates or detoxifying by environmental factors. However, this process consumed a lot of time and cost. Besides, most of the metal ions, especially copper which is capable to bioaccumulate in aquatic organism and at the elevated level may cause physiological and biochemical alteration which leads to mortality. Environmental monitoring is the initial step presupposed evaluating the potential toxicity of effluent gushing at its purpose to discharge, avoiding the determining effects of contaminant in water bodies. Due to the high sensitivity of the aquatic life towards dissolving toxicant, the fish has been utilized as the biological measurement (Biomarker) to indicate the existence of toxicant exposure and/or the impact towards the evaluation of molecular, cellular to physiological level. Thus, this paper gives an overview of the manipulation of fish as a biomarker of heavy metals through behavior response, hepatocyte alteration, enzymatic reaction and proteomic studies which have proven to be very useful in the environmental pollution monitoring

Aluminium induced physiological and biochemical changes in freshwater fish Cyprinus carpio Var.Communis

Qualitative aspects of toxicology are important because they are fundamental to the safety evaluation process in which, one first determines the toxicologic profile of the substance and then establishes how the chemical can be employed safely to prevent injury (Plaa, 1982). According to Durham (1974), toxicity is the ability of a chemical molecule or compound to produce injury once it reaches susceptible site which is determined by the dosage. Cairns (1984) reported that from a regulatory point of view, toxicity tests are used for three major purposes; they are 1. screening of chemicals and products, ii. establishing limits and iii. monitoring; the author further stated that bioassay test can be used to establish the maximum acceptable concentration of a pollutant in a given environment without deliberate application of the chemical causing any unfavourable biological consequences

Butachlor Induced Alterations in Haematologcal Parameters of Schizothorax niger Heckel

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