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Subject: Aquatic Animal Health Management × Author: BHOOLESHWARI, × End date: 2022 × Start date: 2022 ×
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    ThesisItemOpen Access
    BIOACCUMULATION AND DEPURATION OF PESTICIDE ACEPHATE BASED ON HISTOLOGICAL CHANGES IN COMMON CARP (Cyprinus carpio) (LINNAEUS, 1758)
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2022) BHOOLESHWARI,; SHIVAKUMAR M.
    The extensive use of pesticides has led to adverse effects to human health as well as other non-target species and the environment. Pesticides can thus act both indirectly to decrease the food supply, and directly by increasing concentration in the food chain itself on the ultimate predator. Only around 0.1 percent of pesticides are believed to reach the intended organisms, with the rest polluting the environment and causing environmental harm. They can be transferred through food chain, to fish and ultimately reach to humans. Acephate, an organic compound pesticide and its metabolite methamidophos are common organophosphorus insecticide used for crop protection. High uses of acephate and methamidophos have induced health issues and environmental pollution. Fishes are often at the front line of manifesting toxicological effects when exposed to pesticides in aquatic ecosystems. The present study was carried out to investigate the bioaccumulation and depuration of pesticide acephate based on histological changes of Cyprinus carpio. Acute and Chronic toxicity of acephate were analysed by histological changes and physiological changes during exposure. The lethal toxicity of Acephate to fingerlings of Cyprinus carpio exposed for 96h was found to be 850.41ppm. Study was conducted in accumulation phase (sublethal toxicity studies) for the 28days and after completion of accumulation phase fishes were exposed to depuration phase (exposed in clear water) for the 28days. The effect of sublethal concentrations of Acephate ( 1/5th of LC50 i.e.170.082 ppm and 1/10th of LC50 i.e. 85.041 ppm ) was studied on physiological, histological of acephate for a period of 28 days. In accumulation phase physiological parameters such as oxygen consumption rate, ammonia-N excretion rate, food consumption rate, Oxygen:Nitrogen ratio had 98 decreased significantly and at the end of the depuration phase it has slightly increased at both sublethal concentrations of acephate as compared to control group. Damages in vital organs of the fish tissue i.e. gills, liver and kidney resulted that the use of acephate is toxic for the fishes even in the lower concentrations. After 28 days of accumulation, the fishes are exposed to freshwater which showed slowly recover in tissues structure. By this, it can be concluded that fishes can remove accumulated toxic content from body if we provide cleaner environment. Hence, the present investigation recommends the utility of physiological and histological responses as diagnostic tools to assess toxic effects in fishes. All the results were statistically significant at P<0.05. KEY WORDS:Acephate, Lethal toxicity, Cyprinus carpio, Bioaccumulation, Depuration, Physiology and Histology .