Arsenic Exposure Affects Embryo Development of Sea Urchin, Paracentrotus lividus (Lamarck, 1816)

Toxicity tests were performed with embryos of Paracentrotus lividus to investigate the toxicological effect of two arsenic species: arsenate (AsV), expected to be more toxic, and dimethyl-arsinate (DMA) expected to be less toxic. Exposures to toxicants were performed at different developmental stages in order to identify the most sensitive phase of embryological development. Statistical analysis revealed a high significance of each factor (Molecule, Concentration and Time of exposure) and their interaction for the dependent variable “Percentage of normal-shaped plutei”. In particular, the 8 cell stage was the most sensitive to arsenic; at a concentration of 50 μg L−1 DMA proved to be more toxic than AsV, resulting in nearly 50 % of normal-shaped plutei against the 74 % recorded for AsV. Starting the administration of arsenic at the morula stage, arsenate proved to be significantly more toxic when compared to DMA.