Assessing the sensitivity of Caspian Kutum (Rutilus kutum) and the endangered Caspian trout (Salmo trutta caspius) to acute toxicity of nonylphenol

Toxicity tests are commonly used as a tool to determine the standards of water quality for chemicals and to discover appropriate organisms as bioindicators in toxicological studies, and also could be used as an essential tool for evaluation of the pollutant effects in aquatic ecosystems. The aim of the present study was to evaluate the sensitivity of two Caspian fish species, Caspian trout as an endangered species and Caspian Kutum using the static acute toxicity in response to nonylphenol, which is widely discharged into the Caspian Sea environment.The fish were exposed to various concentrations of nonylphenol for ۹۶ hours to determine the LC۵۰. The experimental nonylphenol concentrations were consisted of five exposure groups for each species: ۱۰۰, ۱۵۰, ۲۰۰, ۲۵۰, and ۳۰۰ ?g/l for Caspian trout; ۴۰۰, ۸۰۰, ۱۲۰۰, ۱۶۰۰ and ۲۰۰۰ ?g/l for Caspian Kutum, with a control group for each of them.Using probit analysis, the ۹۶ h LC۵۰ of nonylphenol to Caspian trout and Caspian Kutumwas determined to be ۲۰۴.۷۸ and ۱۲۶۲.۳۶ ?g/l, respectively. In addition, Caspian trout was approximately ۶ times more sensitive than Caspian Kutum. Nonylphenol was reflected to be \"highly toxic\" to Caspian trout and \"moderately toxic\" to Caspian Kutum. The results could be considered in preparing plans for conservation and restocking management of Caspian Kutum and the endangered Caspian trout.

کلیدواژه ها:

Nonylphenol ، Toxicity test ، Caspian kutum ، Caspian trout