[Embryo-toxic effects of nickel sulfate in Paracentrotus lividus: preliminary observations]

A primary objective of the work described here was to determine the embryo-toxic effects induced by Nickel Sulfate upon the development of the Paracentrotus Lividus. Different concentrations of Nickel Sulfate have been dissolved in containers with not foul sea-water. The fecundation took place in the containers and verified by constant observations with a light microscope. The development of the Paracentrotus 1. was totally blocked at a concentration of 0.5 M.10(-2) of Nickel Sulfate, while an enormous development was observed at concentrations of 0.5 M.10(-3) and 0.5 M.10(-4). Finally, a concentration of 0.5 M.10(-5) caused a slow development. A normal development was observed only at a concentration of 0.5 M.10(-6). Our results support various hypotheses on the mechanism of action of the Nickel Sulfate as an inhibitor of the normal development.