Toxicological study of some aquatic weed killers herbicides to nile fish

The extensive growth of aquatic weeds results inagricultural problems by hindering irrigation systemparticulary in Egypt which use channel irrigation system.In order to overcome previous problem, periodicalerradication of weed grow~th is performed.II’L&nual and chemical control were ear-r-Le d out butrecently mainly the use of chemical weedicides hasextensively increased.During spraying river, canal or other vvater channels.The effect of these chemical weedicides not only inhibitweed grovnh but also affecting all aquatic organisms.from the economic point of view fish which represent one9f most important popular animal protein, herbicidescontamination result in an increase in their morbidity a~dmortality rates 0The preceeding fact attract our interest to carry outexperiments to through 15.g~t on the effects of one of thedipyridellium compound mostly used as aquatic weed killerherbicide ”RegIon” on two of most famalief:’ Egyptian Nilefish Clarias lazera a~d Tilapia nilotica~~periments were carried out on Clarias lazeru withavc.rege weight ranging from (65-90g.) and 20 cm. avaregelength, while in case of Tilapia nilotica Nile fish used