ACUTE AND CHRONIC EFFECTS OF STAM NOVEL FLO~® (COMMERCIAL SOLUTION) AND ITS ACTIVE INGREDIENT PROPANIL IN Daphnia magna

摘要

Freshwater ecosystems are frequently subjected to the input of xenobiotics, including pesticides. Impacts in non-target organisms regarding these scenarios are widely reported. Considering their key-position in lentic ecosystems, daphnids are generally used as bioindicators. This study purposes to evaluate the effects of the exposure to Stam Novel Ho 480~®, a currently used amide-herbicide in Portuguese crops, and to its active ingredient (Propanil) on survival and reproduction of Daphnia magna. The acute assays showed that the 48hr-EC50 obtained for Stam Novel Flo 480~® (3.554 mgL~(-1)) was almost twice of that determined for his active ingredient Propanil (2.109 mgL~(-1)), therefore being the latest more acutely toxic to D. magna. The chronic assays revealed slight differences between the effects of both compounds in the somatic and population growth rates and in fecundity. In general, this herbicide promotes changes in survival rates and in life-history traits of D. magna at very low concentrations.