Effects of the organophosphate pesticide Folidol 600® on the freshwater fish, Nile Tilapia (Oreochromis niloticus)

Nile Tilapia (Oreochromis niloticus) juveniles were exposed to different concentrations of Folidol 600 (R) in static toxicity tests. The 24, 48, 72 and 96 h LC50 values of Folidol 600 (R) to O. niloticus were 17.82, 8.91, 4.00 and 2.70 mg L-1, respectively. The values of hematological parameters increased, and inhibition of cholinesterases activity (AChE, BChE and PChE) in plasma of fish exposed to the higher concentrations of pesticide reached 94%. Furthermore, the exposure of Tilapia to Folidol 600 (R) caused an increase of 4%, 20% and 38.4% in oxygen consumption at 0.1, 0.5 and 1.0 mg L-1, respectively. However, exposure to 2.5, 5.0 and 10 mg L-1 caused a decrease of 33.6%, 35.2% and 42.4% in oxygen consumption relative to the control. The ammonium excretion of fish exposed to 0.0, 0.1, 0.5, 1.0, 2.5, 5.0 and 10.0 mg Folidol 600 (R)/L was 0.12, 0.18, 0.30, 0.33, 0.37, 0.36 and 0.33 mu g/g/min, i.e., 50%, 150%, 175%, 208%, 200% and 175% increase, respectively, relative to the control. Published by Elsevier Inc.