Haematological Changes Induced by Short - Term Exposure to Copper in the Indian Freshwater Fish, Notopterus Notopterus (pallas)

The health of fish can be affected by environmental factors (stress), nutrition as well as by pathogens. Stress in fish may be induced by various abiotic environmental factors such as changes in water temperature, pH, oxygen concentration and water pollutants including pesticides, insecticides (Meier et al., 1983; Lebelo et al., 2001), petroleum products and heavy metals (Witeska, 1999). Biotic interactions such as predator pressure, parasitic invasions or strong competition with other organisms or among the fish in overcrowded areas and by human activities related to fish rearing and harvesting (manipulation, transport) can also be a source of stress to fish (Witeska, 2005). Stress reaction involves various physiological changes including alteration in blood composition and immune mechanisms. Stress also induces changes in blood cell numbers and activities. An increase in red blood cell count and volume, and hemoglobin level usually has been reported in fish subjected to stress (Wendelaar Bonga, 1997). The increase in the number of circulating RBC is thought to be associated with the release from reservoirs and even division of circulating cells in fish subjected to low oxygen tension (Murad and Mustafa, 1988). A decrease in white blood cell count, especially of lymphocytes usually occurs in fish subjected to stress (Ellsaesser and Clem, 1986). Heavy metal toxicity invariably reduces white blood cell count particularly lymphocytes (Witeska, 2005) leading to compromised immune responses in the affected fish. The aim of this study is to investiABSTRACT The normal ranges of blood chemistry and the effect of copper sulfate was studied in Indian fresh water fish, Notopterus notopterus. The blood serum biochemical components like, hemoglobin, proteins, urea, urea nitrogen, cholesterol, and glucose levels were determined during the phase of reproductive cycle. Toxic level (LC 50 ) of copper sulfate was found to be 30ppm. Under this concentration (30ppm) after exposure to 96hr the haematological parameters such as glucose, protein, urea, urea nitrogen, cholesterol, creatinine and haemoglobin content were estimated in the blood serum. A significant decrease (p < 0.001) in the biochemical profile such as protein, glucose, urea, urea nitrogen and creatinine were observed; where as haemoglobin (p < 0.001) and cholesterol (p < 0.01) levels in the blood of exposed group was significantly (p < 0.001) higher than that of the control group. The results suggest that the reduction in the above biochemical levels of blood serum may be because of stress due to copper concentration.