Aquatic toxicity testing using the nematode,<i>Caenorhabditis elegans</i>

Abstract

Abstract A promising aquatic toxicity test has been developed using a species of free-living nematode, Caenorhabditis elegans. The testing was performed with soluble forms of Ag, Hg, Cu, Be, Al, Pb, Cr, As, Tl, Zn, Cd, Ni, Sr and Sb. The LC50 values for 1 to 4 d of exposure were determined and compared to the published invertebrate data. With Caenorhabditis elegans Pb, Cr and Cd were found to have the lowest 96-h LC50 (0.06 mg/L) and Sr had the highest LC50 (465 mg/L). All the metals except As have a significantly lower 96-h LC50 (from 20 to 15,000 times lower) than 24-h LC50. Comparison with published data for other invertebrates indicated that Caenorhabditis elegans was more sensitive to Pb, Cr and Be and less sensitive to As than any of the other organisms that have been tested. Given the ease in culturing and the extensive knowledge of the basic biology of Caenorhabditis elegans, coupled with the ecological abundance of nematodes, the method is worthy of further study to determine its usefulness as an aquatic test species.