Hermetia illucens (Black soldier fly) Larvae as a Sustainable Effective Feed Ingredient in Catla catla: Nutritional, Immunological and Gut microbe outlook a Review

Aquaculture sustainability requires replacement of protein sources to reduce dependence on traditional fishmeal. Black soldier fly larvae (Hermetia illucens, BSF) have revealed as a promising functional ingredient due to their high protein, lipid profile, bioactive compounds, and probiotic capacity. Because of their excellent nutritional profile and affordability, insect meals, (BSFL) have the potential to be utilized as a source of protein in animal feed.This review summarizes the nutritional make-up, amino acid and fatty acid profiles, digestive enzyme responses, immune modulation, haematological changes, gut microbiome alterations, and histopathological end-results associated with BSF-based diets in Catla catla. Demonstrations suggests that moderate inclusion levels enhance growth performance, metabolic efficiency, immune status, and gut microbial balance. However, excessive replacement may induce physiological stress and reduced microbial diversity. The review highlights BSF larvae as a sustainable feed resource capable of improving fish health while contributing to circular bioeconomy and waste bioconversion systems.