Author / Editor: Iratxe Menchaca, María Jesús Belzunce, Javier Franco, Joxe Mikel Garmendia (AZTI-Tecnalia)
Content: The reproductive cycle of the sea urchin, Paracentrotus lividus (Lamarck 1816), was studied on the Basque coast (innermost part of the Bay of Biscay), to establish the temporal availability and the quality of gametes to be used in routine toxicity tests. Samples were collected monthly from January to December 2007, at 2 relatively adjacent locations; these differ in their wave exposure and algal communities. According to one year results, spawning took place at the end of winter. The maturity period was longer and embryogenesis success was higher at the more sheltered site. Factors such as hydrodynamic conditions and food type could explain the observed differences in the reproductive cycles, between the locations. The sheltered site appears to be a suitable locality to sample the sea urchins, necessary for routine bioassays; this is related to the good quality and availability of gametes for almost the whole of the year.