Short CommunicationAcute toxicity of cadmium against catfish Heteropneustes Fossilis (Siluriformes: Heteropneustidae) in static renewal bioassays

Abstract

Static renewal evaluation of the acute toxicity of Cadmium Chloride against the freshwater fish Heteropneustes fossilis was conducted in the laboratory. The 96h LC₅₀ was in the low mg/l range (by international protocols). Probit-log analysis was used to determine the LC₅₀ values at different exposure periods. The upper and lower confidence limits and slope functions were calculated. The LC₅₀ values for Cadmium Chloride at 24, 48, 72 and 96 h are 620.34, 414.59, 384.88 and 360.50 mg/l, respectively. The upper confidence limits were 645.59, 433.27, 394.72 and 380.32 mg/l for 24, 48, 72 and 96 h and lower confidence limits were 595.33, 395.87, 374.34 and 337.55 mg/l, respectively.

Keywords/phrases: Bioassay, Cadmium, Catfish, Heavy metal, Toxicity

Ethiop. J. Biol. Sci., 7(2): 185-191, 2008