Can echinoculture be a feasible and effective activity? Analysis of fast reliable breeding conditions to promote gonadal growth and sexual maturation in Paracentrotus lividus

Paracentrotus lividus gonads have been considered a delicacy since the time of ancient Greece; nowadays gonads are marketed fresh, frozen and pasteurized all over the world. Due to commercial fisheries and destructive harvesting methods employed to meet market demand, a dramatic depletion of P. lividus was registered in Europe, especially along the Mediterranean coasts, with a complete disappearance of urchins from areas of former abundance. In this study, we evaluated through different biological outcomes the efficacy of a specific breeding condition characterized by set light/dark regime, a controlled Recirculating Aquaculture System (RAS) and the supply of artificial diets (MD, Macroalgae; MSD, Maize and spinach and PD, a commercial pellet used in fish aquaculture) to ensure a rapid gonadal growth and promote an effective maturation of gametes of P. lividus. Date reported demonstrate that the breeding condition was extremely efficient after just three weeks in regard of the most effective diet MSD, with an increase of the Gonadal Index (GI) from a complete spent stage of 135%. The commercial and biological goodness of these gonads was tested with fecundation and embryo development tests, in addition to a scrupulous histological analysis. The maturation of gonads continued for the 9 weeks of treatment with a final GI value of 19.24 ± 2.95, an increase of about 340% if compared with the beginning of the treatments. The breeding conditions presented in this study proved that Echinoculture could be a feasible commercial activity and can cope in supplying healthy gametes for an eventual repopulation process.