Lipid content and Fatty acid composition in the edible sea urchin Paracentrotus lividus gonads reared in land- and sea-based systems with two dietary treatments.

The edible sea urchin, Paracentrotus lividus, is the most commercially exploited echinoid in Europe. In recent years, there is considerable interest and investment in the development of sea urchin aquaculture (echinoculture) as a new aquaculture industry. The objective of this study was to evaluate two artificial diets for the sea urchin Paracentrotus lividus and to assess their effects on quality through feeding experiments in land-based and sea-based systems. Experiments have been performed utilizing a sea-based system by the CNR team in Taranto (Trial 1) for two months and a land-based facility by the University of Cagliari team (Trial 2) for one month. The utilized diets were: Diet 1, a pellet made from vegetable flour, manufactured by a feed producer from Portugal; and Diet 2 formulated with 50% of Diet 1 and 50% of fresh Ulva sp. At the end of experiment the lipids content in the gonad of sea urchins were higher than those of wild in the two on-growing systems. At the start of the Trials, wild samples showed higher levels of SAFA represented mostly by palmitic and miristic acid, and lower values of MUFA represented by oleic and palmitoleic acid, while PUFA were characterized by EPA, arachidonic, and ?-linoleic acid. After the dietary treatments the FAs profile significantly changed in both in Trials showing a similar fatty acid composition in macro groups. The highest proportion of PUFA were due to the high values of linoleic and linolenic acids, followed by SAFA and MUFA with similar concentrations characterized by oleic and palmitoleic acid, and palmitic and miristic acid, respectively. The results showed that in the short time the influence of the feed will exert a huge impact on the nutritional composition of the sea urchin gonads and these effects could be relevant for the handling processes of echinoculture in the Mediterranean area.