Abstract

The present study aimed to evaluate acute toxicity tests for three selected herbicides: Alachlor, Atrazine and Diuron using turbot flatfish. Larvae were more sensitive than turbot embryos to all pesticides. Median lethal concentrations of the selected pesticides during a 48 h and 96 h exposure for turbot embryos and larvae were, respectively: alachlor, 2177 and 2233; diuron, 10076 and 7826 and atrazine, 11873 and 9957 µg/L. On the basis of the obtained acute toxicity data, all compounds wereincluded among substances highly toxic to fish, in the following order: alachlor> atrazine> diuron. At higher concentrations, pesticides caused a significant increase in embryo mortality. Surviving organisms suffered a significant decrease in hatching success, malformations (embryos), pericardial oedema and skeletal deformation (larvae). All herbicides appear to be teratogenic to the turbot early life stage. Furthermore, the three selected pesticides differed in their toxicity to the fish.

Key words: Turbot, early life stage, acute toxicity, sublethal effects, herbicides.