The use of in vitro (fish cell lines) is a cost-effective, very rapid, and informative tool for toxicological assessments. Using the neutral red (NR) assay, we compared acute toxicity (20hEC50) twenty-six chemical substances on rainbow trout gonad line (RTG-2) with their vivo to Barbados Millions Poecilia reticulata (48hLC50, OECD 203) crustacean Daphnia magna (48hEC50, 202). 20hEC50 values obt...