Effects of Ostreopsis cfr. ovata (Dinophyceae) toxicity on Paracentrotus lividus development.

The effects of Ostreopsis cfr. ovata clonal cultures towards the gametes and embryos of the sea urchin Paracentrotus lividus have been evaluated. The benthic dinoflagellate showed a significant toxicity towards sperms which have exhibited a drastic reduction of their fertility with the increasing of the microalgal concentration. A deleterious effect was also observed on the embryos cleavage. These data should be considered preliminary and will help us to better understand the effects that this allochtonous microalga might have on marine life in temperate waters.