Toxicological Studies on the effect of Pestban in Tilapia nilotiea with a Trial of its Tteatment

Pestban is broad spectrum organophosphate insecticide withgrowing concern due to its aquatic toxicity especially freshwater fish as(Orechromis niloticus) locally called Nile tilapia is an important popularfish species in Egypt and is abundant in the natural water source. Greenbarley has many antioxidants such as antioxidant vitamins,superoxidismutase, catalyze enzyme and chlorophyll which chelate andadsorb toxic materials as pesticide.This work was planned to investigate:I-Determination of the median lethal concentration of Pestban whichcause death to 50% of tilapia fish (45±5g, I2.5±0.5cm) at 96-h.Thisexperiment used 180 tilapia fish divided into ten concentrations (0.07:0.6mg/l) of Pestban.2- Study protective effect of barley grass powder (10% and 20%in diet)on toxic effects of pestban this experiment used 540 tilapia fish dividedinto 4 groups as follows:GroupI: control (-ve) basal diet.GroupII: (control +ve) barley grass powder 10%