Effects of metal ions and CCl4 on sea urchin embryo (Paracentrotus lividus).

The determination of embryotoxicity is an experimental tool for detecting the risks of environmental pollutants. In this study, fertilized eggs of sea urchin have been observed morphologically during exposure to heavy metal salts or carbon tetrachloride, with the purpose of testing possible differences in toxicity of various classes of poisons. Mercuric chloride is the most active salt, still harmful at 0.25 x 10(-6) M, while potassium dichromate, cadmium chloride and lead nitrate block embryo development at concentrations ranging between 0.25 x 10(-4) and 0.25 x 10(-5) M. Carbon tetrachloride per se does not affect the gastrulation at concentrations up to 3,520 ppm, and fails in potentiating the toxicity of the studied metal salts. The selective susceptibility of the development phases of sea urchin embryos to different compounds renders this simple morphological study a sensitive and reliable model for predicting the toxicity of environmental pollutants.