Integrated aquaculture of whiteleg shrimp Litopenaeus vannamei and European seabass Dicentrarchus labrax: impacts on performance, welfare, blood physiological response, carcass traits, productivity, and farm profitability

Abstract

Seabass farmers suffer from a long-lasting production period of at least 18 months, causing a long-term gap in financial income and payback. This study investigated the integration of Litopenaeus vannamei with Dicentrarchus labrax aquaculture allowing seabass farmers to earn a consistent income 2–3 times a year. Six treatments (seabass alone “control group,” seabass with 5, 10, 15, 20, and 25 shrimp in the fish tanks) were tested in triplicate and expressed as S0, S5, S10, S15, S20, and S25, respectively. Seabass was housed at a standardized density (12 fish/tank, each 3500 L water). Fifteen hapas (each 1 m × 1 m, 700 L water volume) were installed in 15 rearing tanks to hold the experimental shrimp, occupying 20% of the tank’s water volume. Both fish and shrimp received specialized diets during the 90-day experiment. The findings indicated that increasing shrimp density by more than 15 juveniles/hapa significantly (P < 0.05) increased nitrogen by-products (TAN and NH₃) and decreased growth performance and feed efficacy in seabass and shrimp. Moreover, increasing the shrimp density noticeably (P < 0.05) improved the protein content in seabass flesh but declined it in shrimp. Serum and hepatopancreas indicators in seabass and shrimp, encompassing liver and digestive enzymes, lipid profile, cortisol, IgM, antioxidants, and growth immune-related hormones, demonstrated significant (P < 0.05) improvement in groups polycultured with shrimp up to 15 pcs/m² (S15 group). Furthermore, integrating shrimp in seabass tanks improved gross income, net profit, benefit–cost ratio, and payback period of seabass. The recommended shrimp density when integrated with seabass using a flow-through system is 15 pcs/m².