evaluation of the ability of nano clay on decrease of toxicity ‎effects of environmental pollutants on the caspian sea ‎kutum (rutilus frisii kutum)‎

abstract: when pesticides are present in high concentrations in the environment causing ‎irreparable, metabolic, physiologic and structural damage on the organisms. diazinon and ‎deltamethrin are of the most widely used agricultural pesticides in the northern iran that can ‎enter aquatic ecosystems. anatropous fishes like kutum have most reactions with pollutants ‎because of their spawning in the first spring. kutum is suitable species for toxicity testing in the ‎southern coast of the caspian sea, due to the wide distribution. the aim of present study was to ‎determine the effects of nano-clay in reducing the fatality rate of diazinon and deltamethrin on ‎the caspian sea kutum. 210 pcs kutum with a mean weight of 24 g were collected from fish ‎stocks syjval and after two weeks of adaptation in laboratory toxicity tests carried out for 96 ‎hours. the results of this study showed that 500 mg / l clay is the greatest losses while 1000 mg / ‎l nano clay increased the death toll is likely to rise due to high water and mud contaminated ‎fish is breathing difficulty.‎