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20111
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Subject: Aquaculture × End date: 2021 × Thesis Type: M.V.Sc. ×
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    ThesisItemOpen Access
    PHYSIOLOGICAL DISTURBANCES IN COMMON CARP (Cyprinus carpio) AS AN INDICATOR OF POLLUTION STRESS
    (KARNATAKA VETERINARY ANIMAL AND FISHERIES SCIENCE'SUNIVERSITY, BIDAR-585226, 2011-09) MUTTAPPA KHAVI; H.R.V.REDDY; A.T.TAMCHANDAR NAIK; K.S.RAMESH; MRIDULA RAJESH
    The use of insecticides is being increasing in the recent years to control the pest in which only 1% of the pesticide applied hits the target pest while, the remaining 99% of the pesticide drifts into the environment contaminating soil, water and biota. This poses a constant threat to the non-target organisms especially to fishes, because pesticides are known to alter their behavioral pattern, growth, and physiology. One of the early symptoms of acute pesticide poisoning is failure of respiratory metabolism, reduction in the food consumption, alteration in absorption efficiency, scope for growth and oxygen: nitrogen ratios of fishes. A static renewal bioassay was conducted to determine the acute toxicity (LC50) of commercial grade Organophosphate insecticide, Quinalphos (25% emulsified concentration) to common carp (Cyprinus carpio). The acute toxicity of Quinalphos to carp fingerlings exposed for 96 h was found to be 2.75ppm. For sublethal toxicity study, the fishes were exposed to two sublethal concentrations (1/10th of LC50 i.e 0.275ppm and 1/5th of LC50 i.e 0.55ppm) with lethal concentration (2.75ppm) for up to 48 hours. The carps were found to be under stress but mortality was insignificant in both sublethal and lethal concentrations. Considerable variation in respiratory rate was observed in both sublethal and lethal concentrations. 84 The effects of this pesticide on the physiological condition were remarkable. Food consumption rate, absorption efficiency, scope for growth and Oxygen: Nitrogen ratio of the fishes was affected when it was exposed to increasing concentrations of Quinalphos. The observed alteration in physiological condition may be a consequence of impaired oxidative metabolism and elevated physiological stress by the fish against quinalphos stress.