biochemical toxicological studies on the herbicide dichlobenil on oreochromis niloticus fish

Summary:-1- The acute toxicity in our study recorded the 96-hr LC~o ofdich10beni1 as 2.2 ppm in Tilapia Nilotica and so dich10beni1 maybe listed under the toxic pollutant to ti1apia ni10tica fish.2- The clinical signs indicated that they there are a dose levelrelationship as at 16 mg/L nervous manifesation were the mostprominent signs, at 812 mg/L respiratory symptoms wereaparent. At dose 0.5 - 4 mg/L weredepression and loss ofvitality in some fish.3- The only postmortum findings observed in dead fish were earlyputrifaction ,paleness of the gills and the liver showed conges-tion with distended gall bladder.4- Biochemical changes:a- The effect of dich10beni1 on crude protein sh ~ a ~g_~t 0.33, 1 and 2.2 ppm exposure. Thisdecrease was a time related rather than a dose related.b- Fish exposed to 0.22, 1 and 2.2 ppm of dich10beni1 showedsignificant decrease to percentage of ether extract tothe dry matter. The decreased was a time related and tosome extent a dose related.c-Values of the soluble proteins in the dorsal musclehomogenate after one month exposure to 0.22 ppm wassiginficant decrease, then increased after two and threemonths but still lower than the control, while the fish