Substitution of Fishmeal with Black Soldier Fly Hermetia illucens Linnaeus, 1758 Larvae in Finfish Aquaculture – A Review

The reliance of aquaculture feed industry on fishmeal has been challenged by ecological, economic, and ethical limitations leading fish nutritionists to look for viable alternatives, and conventional animal-based protein sources showed varying degrees of success in this regard. However, a non-conventional protein source, black soldier fly Hermetia illucens Linnaeus, 1758 larvae (BSFL), received due attention as a focal point in fish nutrition research. Though many studies were conducted on H. illucens as a potential protein source for fish, a comprehensive review is not available. Therefore, this article aims to review the existing literature on the use of BSFL as a fishmeal replacer in aquaculture. The nutrient composition of BSFL varied with the developmental stage and the composition of growing medium. High crude protein levels (40.4–56.2 %) and high crude fat levels (4.8–24.8 %) made BSFL suitable for high protein and high energy diet. Early prepupa was the best stage for harvesting, considering its high crude protein content and dry matter yield and less chitin content. Up to 100 % inclusion levels of BSFL meal were tested in a wide range of fish species. Most studies revealed that up to 50 % of fishmeal replacement would be possible without negative effects on the fish. Notable adverse effects were found beyond 50 % of fishmeal replacement, mainly due to high chitin levels in the pupal stage and high crude fat levels. Harvesting BSFL before the pupal stage and defattening made it possible to replace 100 % of fishmeal without adverse effects on fish.