Abstract
The necessity for seafood-based nutrition in food security concerns the aftereffects of biowaste accumulation. These bioorganic wastes pose significant environmental and health challenges. Thus, bioconversion of wastes through insect-based systems offers a sustainable solution advantageous to the circular bioeconomy. The present study examines the impact of black soldier fly larvae (BSFL) meal integration for fishmeal (FM) substitution in the diet of Cyprinus carpio. Initially, an isonitrogenous formulation of BSFL inclusions at various levels of fish meal substitution, including D0(control), D1(25%), D2(50%), D3(75%), and D4(100%). On a dry matter basis. Among the diets, D2 and D3 BSFL diets show significantly improved morphometric parameters such as weight gain (respective result), length gain (respective result), and specific growth rate (respective result) compared to the control. Feed conversion ratio (FCR) was lowest at D2, while protein efficiency ratio (PER) peaked at D3, indicating enhanced feed utilization. Physical properties, including sinking velocity and water stability, were optimal in D3 and D4BSFL diets (respective results). Haematological, histological, and serum biochemical analyses further justified the improvement in physiological as well as health status at D2 and D3inclusion levels (respective results). Furthermore, digestive enzyme activities (amylase, protease, trypsin) were elevated in higher inclusion level D4 (respective results), suggesting nutrient assimilation. Additionally, antioxidant enzyme activities (SOD, CAT, GSH, GPx) were significantly higher in the D4 group, indicating improved oxidative stress mitigation; comparatively, lipid peroxidation activity remained lowest in the D0. Overall, the findings highlight that BSFL meal can be utilised for replacing FM in aquafeeds up to 75% without conciliatory effects on growth, health, or nutritional efficiency in C. carpio.
Keywords: Aquaculture, Bioconversion, Black soldier fly larvae, Cyprinus carpio, Larval biomass, Fish meal.