Determina el grado de letalidad del insecticida Fipronil en estadíos iniciales de vida de la “Gamitana”, Colossoma macropomum bajo condiciones controladas de laboratorio. Para la prueba de toxicidad con postlarvas, se evalúa en 6 concentraciones (0.00; 0.12; 0.165; 0.21; 0.255 y 0.30 mg.L-1) y 4 repeticiones por un tiempo de 48 horas y para la prueba de toxicidad con alevinos, se evalúa en 6 concentraciones (0.00; 0.221; 0.276; 0.346; 0.432 y 0.54 mg.L-1) y 3 repeticiones por un tiempo de 96 horas. Determina valores de CL50-48h (0.217mg.L-1) y CL50-96h (0.331mg.L-1), para los estadíos de postlarva y alevín, respectivamente. Además, la máxima concentración no letal para los estadíos de postlarva y alevín es de 0.12mg.L-1 y 0.221mg.L-1 respectivamente. Los peces en estadío de postlarva bajo la acción del Fipronil muestran un comportamiento inusual, nado errático en la colu...

The present study was aimed to determine the lethality of the insecticide fipronil on two early life stages, post-larvae, and fingerling, of Colossoma macropomum, by determining the lethal concentration 50 (LC50). Five nominal concentrations (0.12; 0.165; 0.21; 0.255 and 0.30 mg/L) and a control in 4 replicates per treatment for 48 hours of exposure were used for the post-larvae; and other nominal concentrations (0.22; 0.27; 0.34; 0.43 and 0.54 mg/L) and a control in 3 replicates per treatment for 96 hours of exposure were used for the fingerling stage. The LC50 value was calculated as 0.22 mg/L and 0.33 mg/L for the post-larvae and fingerling stages, respectively. In addition, the maximum concentration that causes no mortality (MCNM) and the minimum concentration that causes mortality (MCM) for the post-larvae stage were determined as 0.12 and 0.15 mg/L, respectively; and 0.16 and 0.22 ...