Comparative Toxicity of Heavy Metals and Interaction of Metals on a Freshwater Pulmonate Snail <i>Lymnaea acuminata</i> (Lamarck)

Abstract

Abstract In static bioassays the toxicity of heavy metal ions against Lymnaea acuminata over 24 … 96 h is tested. The values of the LC 50,96h for the metals tested are, in mg/l: Hg 2+ −0.023; Cu 2+ ‐0.034, Cd 2+ −0.872, Ni 2+ −2.78, Cr 6+ −5.97 and Zn 2+ −10.49. In the combined solutions of Cu 2+ , Ni 2+ and Zn 2+ at least an additive effect of toxicity occurs in the presence of two metals. The same holds for the presence of the three metals; in this case, the relative toxicity against the mixture of two metallic salt solutions appears to be slightly reduced. The acute manifestation of the toxic effect occurs within 48 h, subsequently the relative mortality decreases especially in the mixed solutions.