Determination of EC50 toxicity data of selected heavy metals toward Heterocypris incongruens and their comparison to "direct-contact" and microbiotests.

The sensitivity of Heterocypris incongruens to selected heavy metal ions is discussed. Although the Ostracodtoxkit ® has been present on the market for a few years, data on its selectivity and sensitivity to toxicants is scarce; such data is indispensable when interpreting the results of sediment toxicity. The LC(50) and EC(50) results with the Ostracodtoxkit ® are compared with those obtained with other commercially available "direct-contact" tests (utilizing Hyalella azteca and Chironomus riparius) and microbiotests for assessing the toxicity of aqueous samples (Vibrio fischeri, Daphnia magna, and Selenastrum capricornatum). The sensitivity of H. incongruens to metal ions (Cd(2+)> >Hg(2+)> Cu(2+)>Cr(6+ )>Ni(2+) ≈ Mn(7+)>Zn(2+)>Pb(2+)>Li(1+ )> Fe(3+)) was found to be similar to that of H. azteca and of C. riparius. The Ostracodtoxkit ® has shown itself to be an efficient and reliable element of test batteries for toxicity determination.