Effect of Phenthoate 50% EC on Oxygen Consumption of Freshwater Fish Catla catla

Generally pesticide concentrations are toxic which may be lethal (or) sub lethal concentration in aquatic environment. Lethal concentration cause death of the organisms directly, but the sub lethal concentrations are too low to cause rapid death directly. Oxygen consumption of an animal is the important physiological parameters to assess the toxic stress because it is a valuable indicator of energy expenditure in particular and metabolism in general. Exposure to sub lethal concentrations is reported to increase respiratory activity, resulting in increased ventilation and hence increased uptake of the toxicant. Although, toxicant impairs the metabolic and physiological activities of the organisms, physiological studies alone do not satisfy the complete under toxic stress. Hence it is useful to have an insight in to the histological analysis. The extent of severity of tissue damage is a consequence of the concentration of the toxicant and is time dependent. Also, the severity of damage depends on the toxic potentiality of a particular compound or pesticide accumulated in the tissue. The total oxygen Consumption is one of the indicators of the general well being of the fish. Hence the differential oxygen Consumption can be used as bio-indicator to evaluate the basic damage inflicted on the animal which could either increase (or) decrease the oxygen uptake changes in certain vital tissues like gill, liver and kidney of the Indian major Carp Catla catla exposed to sublethal concentrated (1/10 of 96 hrs LC 50)