PREDICTION OF FECUNDITY IN CHRONIC TOXICITY TESTS ON DAPHNIA-MAGNA

The present study deals with the analysis of fecundity in Daphnia magn a in chronic toxicity tests. Regression models were used to assess the possibility of predicting Fecundity values over the long term on the basis of growth values recorded early in the toxicity test. The result s based on data from toxicity tests with pyridine, cadmium and chromiu m (the last at two different food levels), indicate that such predicti ons are practicable, since the relationship between growth and fecundi ty is strong and robust under the experimental conditions employed. Da maging effects of toxicants on fecundity over 21 d (the usual length o f the Daphnia magna chronic toxicity tests) and/or longer, can be deri ved from body length recorded in shorter exposure to toxicants. (C) 19 98 Elsevier Science Ltd. All rights reserved.