| Popis: |
Pyrethroids are the third most applied group of insecticides worldwide and are considerably used in agrarian and non-agricultural uses. Pyrethroids parade low toxin to mammals, but have extremely high toxin to sh and non-target species. Their high hydrophobicity, on with pseudo-persistence due to nonstop input, indicates that pyrethroids will accumulate in deposition, pose long- term exposure enterprises to aquatic species and eventually beget signicant threat to benthic communities and aquatic environments. The present investigation was undertaken to study the acute toxicity of the insecticide Cyphenothrin and the resulting behavioral alterations in the Indian major carp, freshwater sh Cirrhinus mrigala. The experimental sh were divided into groups of 10 (n=10) and exposed to different concentrations of the test pesticide for 24, 48, 72, and 96 hours. The 96- hour LC50 was found to be 30μg/l. Sub-lethal concentration was xed based on LC50 value is 6μg/l (1/5th of LC50) of the insecticide Cyphenothrin for a period of 10, 20, 30 and 40 days. Behavioral patterns and oxygen consumption were studied in sub lethal concentrations. Regular observation was made throughout the exposure period to determine the long-term behavioral changes in the test sh. The sh displayed erratic swimming behavior that increased over the days of exposure. Behavioral anomalies such as whirling cork movement, altered opercular movement, altered n movement and physiological changes such as dyspigmentation and altered mucus secretion were observed. Dissolved oxygen content was measured at 24, 48, 72 and 96 h to assess the impact of toxicant exposure on oxygen consumption. Oxygen consumption of exposed shes showed signicant decrease at sub lethal concentrations. It is concluded that cyphenothrin is highly toxic to ngerlings of Cirrhinus mrigala and severely affects their physiology and behaviour. |
