Using black soldier fly larvae (Hermetiaillucens) converted the bioflocs produced with shrimp solid waste

Abstract

Waste generated during aquaculture can be converted into bioflocs. Black soldier fly larvae (BSFL) are a valuable resource for the treatment of organic waste. This study evaluated the effect of feeding BSFL with bioflocs for the first time with the aim of providing a new approach for the resource utilization of aquaculture solid waste. Six treatment groups were established by feeding BSFL with fermented bioflocs (A1), bioflocs (B1), fermented wheat bran (A2), wheat bran (B2), fermented mixed diet (A3), and mixed diet (B3). The survival rates (SR) of the six treatment groups were not significantly different. The crude protein and lipid contents of the final BSFL were 50.9–63.94% and 3.96–7.73%, respectively, in the six treatment groups. The BSFL of B2 had the highest crude protein and lowest crude ash content while those of B1 had the lowest crude protein content and highest crude ash content. Oleic and linoleic acids were the predominant fatty acids in BSFL for all groups (>53.25%) and B3 BSFL contained three essential fatty acids (EFAs). By analyzing the effect of BSFL culture and biofloc reduction, we determined that bioflocs and wheat bran mixed at a ratio of 6:4 (dry matter) is ideal for cultivating BSFL. Overall we found that BSFL can directly treat bioflocs and the bioflocs intend provide ideal nutrients for BSFL, which implies a potential method for cleaner production in aquaculture.