Estimation of Acute Toxicity of Ammonium Sulphate to the Fresh Water Catfish,Heteropneustes fossilis——Ⅰ.Analysis of LC_(50) Values Determined by Various Methods

摘要

The acute toxic effects of ammonium sulphate to fresh-water catfish,Heteropneustes fossilis(H.fossilis)have been studied by determining LC50 values with 95% confidence limits,by the graphic method,the logistic method,the Spearman and Karber method and the trimmed Spearman-Karber method.The trimmed Spearman-Karber method was found the most ideal for ammonium salt toxicity test.The flaws in the trimmed Spearman-Karbr method are also discussed.