MORTALITY RATES OF JUVENILE AFRICAN CATFISH (CLARIAS GARIEPINUS) EXPOSED TO DICHLORVOS INSECTICIDE

Résumé

This study investigated the impact of Dichlorvos (DDVP) insecticide on the mortality rates of fish exposed to various concentrations of DDVP. Juvenile African catfish were procured and acclimated for two weeks in dechlorinated water under natural conditions. A total of 150 fish were randomly allocated into five treatment groups in triplicate, each containing 10 fish, and exposed to various concentrations of DDVP based on a 96-hour LC50 of 0.00056 ml/L. The experimental groups included T1 (control, no DDVP), T2 (0.000112 ml DDVP/L), T3 (0.000224 ml DDVP/L), T4 (0.000336 ml DDVP/L), and T5 (0.000448 ml DDVP/L). Temperature and pH of experimental water were monitored daily. Fish mortality was assessed at multiple time points throughout the experiment, with dead fish removed promptly to prevent oxygen depletion. Results showed that mortality rates were significantly (p < 0.05) higher in T4 (85.00 ± 7.07%) and T5 (100.00 ± 0.00%) compared to T1 (0.00 ± 0.00%), T2 (15.00 ± 7.07%) and T3 (20.00 ± 14.14%). T4 and T5 exhibited the highest mortality rate among all treatments. This study highlights the detrimental effects of DDVP on the health of Clarias gariepinus, with higher concentrations leading to increased mortality rates.