Influence sur la survie jusqu'a eclosion des embryons de carpe commune (cyprinus carpio l.) apres traitement, pendant la fecondation et le developpement precoce, par le carbendazime, un fongicide antimitotique de synthese

The toxicity of the systemic antimitotic fungicide carbendazim, a benzimidazol compound, was studied both by trout and common carp insemination, as well as on the early development of the common carp.The toxicity is several grades of magnitude higher for these stages of the vital cycle compared with the effect on the adult stages: whereas The Pesticide Manual states that for the adult Carp, an LC₁₀₀ (24 h) > 1000 mg 1⁻¹ we find, during insemination at pH 9: LC₁₀₀ (30 min) < 5 mg l⁻¹ and during insemination at pH 7: LC₁₀₀ (30 min) <2.5 min l⁻¹.During early development we find, for instance, LC₁₀₀ (30 min) < 5 mg 1⁻¹ before the end of activation and LC₁₀₀ (24 h) < 1 mg l⁻¹ before the end of epiboly.In the course of insemination, the egg is more sensitive to carbendazim at pH 7 than at pH 9: this difference may be attributed to a greater solubility of the non ionic form of the molecule in the biological membranes.The resistance of the embryo to short treatment grows at the end of activation. This may be attributed to the decrease of the shell permeability during activation.Before the end of activation, the resistance to short intoxication seems to be able to fluctuate, which perhaps corresponds to the existence of sensitive stages in the mitotic cycle.The resistance to an over 24-h exposure increases abruptly at the end of epiboly, which could correspond to a protective part played by the enveloping layer.We suggest the possibility of classifying aquatic pollutants by correlating their physiological mode of action to the resistance profile of the fish embryo.The carp egg seems to be a favourable biological model for studying the effects of aquatic pollutants.