[Phototactic behavior of Daphnia carinata as an indicator of chromium biotoxicity].

Abstract

The study on the phototactic behavior of Daphnia carinata clone Dc42 as an indicator of chromium biotoxicity showed that the phototaxis inhibition ratio (Rpi) of D. carinata could better indicate the chromium status in water. There was a negative linear correlation between phototactic index (Ip) and Cr6+ concentration in standardized K2Cr2O7 solutions (R2=0.8089, P<0.001). The detection limit of Cr6+ by Ip was 0.056 mg x L(-1), much lower than that of LC50 or EC50, and the mean precision index for detection reached up to 5.46%, which suggested the sensitivity, precision and reliability of this method in monitoring chemicals biotoxicity.