Gonads of Paracentrotus lividus are considered a delicacy and the increasing market demand depleted several wild stocks. In this context, sustainable echinoculture can play an important role for supplying commercially gonads and also for local restocking. Nevertheless, the success of this activity largely depends on the development of valuable hatchery techniques, establishment of adequate rearing conditions and nutritional balanced diets for the different life cycle stages.
This aquaculture research is part of a multidisciplinary project called "Ouriceira Aqua: Aquaculture and Enhancement of Gonad Production in the Sea Urchin Paracentrotus lividus", which launched in July 2017, funded by the European Commission under the Operational Programme MAR2020. The general goals of this project are to improve the aquaculture of the sea urchin P. lividus using innovative approaches for broodstock conditioning, larval development, growth and optimization of gonadal yield. The project seeks to evaluate the potential rearing of this species, contribute to develop technological aspects that are still bottlenecks and increase gonad yield in adult sea urchins in recirculating aquaculture systems. In this context, firstly the project intended to achieve the gonads' maturation to produce viable larval rearing and perform larval nutrition experiments in order to optimize the survival rate and settlement success, and then improvement of the somatic growth with diets that can promote faster growth. Enhancing roe of the sea urchin P. lividus were also investigated using artificial diets and manipulating zootechnical parameters, in order to obtain gonads with the quality demanded by consumers: larger, with desirable colour, texture and flavour.
Regarding the potential aquaculture of P. lividus, results showed advances in fertilisation protocols, improvement of larval production and settlement with new mixtures of microalgae and improvement of juveniles' growth with the developed extruded diets. Regarding the enhancement of gonads, some jellified diets with selected vegetables and new formulations of extruded diets, that were not previously used, can improve the productive process and gonad quality. The effects of these diets have been studied to determine which provide the factors that can influence the marketability of sea urchins. In this way, insights and results from the Ouriceira Aqua project will be analysed and discussed.
Acknowledgements
This project has the financial support of Operational Programme MAR2020 through the project 16-02-01-FMP-0004: Ouriceira Aqua: Aquaculture and Enhancement of Gonad Production in the Sea Urchin (Paracentrotus lividus). Also, this study had the support of Fundação para a Ciência e Tecnologia (FCT), through the strategic project UID/MAR/04292/2019 granted to MARE - Marine and Environmental Sciences Centre.