Innovative Feed Solutions for Paracentrotus lividus (Lamarck, 1816) Farming: Exploiting Fish and Vegetable By-Products for Sustainable Aquaculture

Paracentrotus lividus (Lamarck, 1816) is a commercially valuable species in the Mediterranean Sea, and the development of suitable feeds for juvenile rearing remains an important challenge for full-cycle aquaculture. In this study, we evaluated two experimental formulated diets containing anchovy-processing by-products and carrot peels as main ingredients, using a commercial diet as control. The diets were tested for 84 days on three size classes of P. lividus under controlled recirculating aquaculture conditions. Growth, feed intake, somatic growth rate, feed conversion ratio, gross apparent digestibility, and nitrogen assimilation were assessed. Our results demonstrated that both experimental diets could sustain the growth of sea urchins. However, growth varied significantly across diets and size classes and the two diets showed different results in terms of somatic growth rate and feed conversion ratio. Our findings suggest that eco-friendly feeds derived from industrial waste by-products can be used for sea urchin aquaculture. However, further research is needed to optimize feeding protocols and understand the underlying mechanisms affecting growth performance and feed assimilation efficiency. The utilization of food waste in aquaculture can contribute to the conservation of overexploited sea urchin stocks and promote sustainable practices in marine resource management.