ECOTOXICOLOGICAL EFFECTS OF DIFLUBENZURON ON MOTILITY, MORPHOLOGY, AND OSMOREGULATION IN PARAMECIUM CAUDATUM

The freshwater ciliate protozoan Paramecium caudatum was used to assess the toxic and functional effects of the insecticide Diflubenzuron. In acute toxicity tests, exposure to lower concentrations of Diflubenzuron led to a slight decrease in cell motility, whereas higher doses induced abnormal rocking behavior, ultimately resulting in complete immobility. The median lethal concentration (LC50) after 3 hours of exposure was determined to be 300 ppm. Cellular deformities, including swelling, an oval shape, and at elevated concentrations, a reduction in body length and darkening of the cytoplasm, were observed, indicating significant toxic effects. Additionally, leakage of cellular contents suggested membrane damage. Changes in the contractile vacuole activity were noted after 20 minutes of exposure to 25, 50, 75, and 100 ppm, indicating potential disruption of osmoregulatory functions. Altered phagocytosis and vacuolar activity further suggest that Diflubenzuron has substantial physiological impacts on Paramecium caudatum. Due to their rapid growth, short life cycles, and reproducibility, ciliates like Paramecium are valuable model organisms for evaluating the toxicity and physiological effects of xenobiotics.