No abstract

Abstract. Eight‐day‐old striped bass, Morone saxatilus (Walbaum) larvae, and one‐month‐old juveniles were held in varying salinities and exposed to a range of concentrations of potassium permanganate. Lethal concentrations of potassium permanganate for 50% of the larval fish exposed for96h (96h LC50) were 1middot;02, 2 middot;11, 1 middot;41 and 1 middot;73mg/1 for salinities of 0, 3, 6and 9 g/l, respectively; The 96h LC50S for juveniles were 0 middot;96, 3 middot;26, 1 middot;63 and 1 middot;48 mg/l for salinities of 0, 5, 10 and 15g/l, respectively. There were significant differences in 96h LC50 values at different salinities for both life stages. The 96 h LC50 values derived for both life stages revealed a decrease in toxicity as salinity increased from 0 to 3–5g/l. Results indicated potassium permanganate to be toxic in fresh water to striped bass larvae and fingerlings at recommended treatment levels (3 middot;0mg/l).