Cyst-Based Toxicity Tests : Comparison of the Sensitivity of the Acute Daphnia magna Test and Two Crustacean Microbiotests for Chemicals and Wastes
Abstract : This paper statistically evaluates the sensitivity of the acute Daphnia magna bioassay in comparison to that of two crustacean microbiotests : the Streptoxkit F and the Thamnotoxkit F, which make use of larvae of the anostracans Streptocephalus proboscideus and Thamnocephalus platyurus respectively, hatched from cysts. Regression equations were calculated for 146 data pairs, taken from 5 different studies dealing with the acute toxicity of pure chemicals, effluents, river sediments, solid wastes and monitoring wells, and sludges. All comparisons show that there is a significant relationship (p< 0.05) between the acute effects found with the D.magna and the two crustacean microbiotests; correlation coefficients ranged from 0.84 to 0.92.
In the majority of cases, effect ratios between the conventional D.magnaand the microbiotests were within a factor 2 for both pure chemicals and environmental samples.
Variation coefficients for repeated tests on the reference chemicals potassium dichromate indicate a good precision and hence a good degree of standardization of the microbiotest procedures. The evidence provided in this paper demonstrates that the new crustacean microbiotest can be used as low cost alternatives to conventionalD.magnaacute assay.