Mediterranean species as main characters in feeding strategy for the development of sustainable systems and resilient farming. Effects evaluation of four experimental diets administered to larvae, juveniles and adults of European Seabass and to Meagre, on growth performance, gut health and animal welfare.

Aquaculture is a growing wide industry, that until now and in the future represents a sector with enormous potential. Despite that, it is still correlated with environmental issues and ambiental impacts. For several years, both the scientific community and the industry have been working together to make this sector increasingly sustainable and resilient. This doctoral thesis deals with the study and valorisation of alternative ingredients chosen for their nutritional characteristics and potential, with the final aim of giving new inputs to aquaculture to become more sustainable. In particular, this study was focused on: -Evaluation of green technologies applied to production of microalgae biomass. Renewable energy sources, such as geothermal, can reduce the environmental impact of aquafeed production. - The use of by-products from fishery and aquaculture in order to replace fish meal fish oil and soybean meal with microalgae. -Evaluate the effect of experimental diets on different life stages of a commercial species widely distributed in the Mediterranean Sea, European Seabass. - Among two Mediterranean species considered, Meagre is an emerging species, considered a valid substitute for the most widespread commercial species such as Gilthead Seabream and European Seabass. Emerging species are a very powerful tool to reduce pressure on those species already heavily bred. - Organic diets were tested on an emerging species, relating both the sustainability of organic diets and the sustainability of emerging species.