Toxicity of the Herbicide 2.4‐D‐Na to Two Species of Freshwater Prawn of the Genus Macrobrachium

Abstract In batch experiments with exposure for 24 to 96 h Macrobrachium naso and M. dayanum were exposed to solutions of the sodium salt of 2,4‐dichlorophenoxy acetic acid. The LC50,96h are 2.397 g/l for Macrobrachium naso and 2.275 g/l for M. dayanum. No mortality was observed in solutions of 2.1 and 1.85 g/l. The differences in toxicity are not dependent on the size of the organisms, but they are species‐specific.