Evaluation of the fertilization capability of Paracentrotus lividus sea urchin storaged gametes by the exposure to different aqueous matrices.

Several experiments were performed to evaluate the fertilization capability of Paracentrotus lividus sea urchin gametes, which are usually used in fertilization tests, but which, until now, were employed only for few hours after spawning. The aim of this work is to evaluate the possibility of performing the bioassay for longer periods, employing 'conserved' gametes. As far as the method, the sperm was stored 'dry' at 4 degrees C; eggs were conserved in an antibiotic solution at 4 degrees C, and they were exposed both to copper solutions as reference toxicant and to aqueous matrices. The use of conserved gametes in the fertilization bioassay lead to EC50 values which were acceptable for about 3 days. Moreover, these experiments permitted to identify the limiting factor: the male gamete.