the effects of pretilachloreon adaptation stage of caspian roach (rutilusrutilus) fingerlings

artificial fertilizers and mainly organophosphate herbicide are used by farmers to enhance their crop and control pests. in order to investigate the effects of pretilachlore, fingerlings of caspian roach were exposed to a range of concentrations of toxin close to those of estuary for 96 h. due to movement of these fingerlings in a gradient of salinity from freshwater to brackishwater some physiological parameters were also measured and compared in these environments. cortisol levels were significantly increased in all groups exposed to pretilachlore, and after transferring to brackishwater the amount of cortisol was increased in control group as well. k+ and cl2- were increased in experimental groups, na+ changes were irregular but more changes were observed in the high concentrations of toxin. the results indicate that, fingerlings exposed to organophosphate herbicides in freshwater, may encounter some problems in physiological adaptation for entering the sea which in turn would have a negative impact on returning adults and brooders.