Effect of full-fat black soldier fly (Hermetia illucens L.) larvae on growth performance, immunological parameters, and gene expressions in zebrafish (Danio rerio)

Document Type : Original research

Authors

1 College of Environmental and Resource Sciences, ZheJiang University, YuHangTang Ave 688, HangZhou, ZheJiang Province, 310058, P. R. China

2 HangZhou GuSheng Technology Company Limited, XiangWang Ave 311118, HangZhou, 311121, P. R. China

3 Yangtze River Delta Health Agriculture Research Institute, Development Ave 133, TongXiang Economic HiTech Zone, TongXiang, 314515, PR China

4 College of Environmental and Resource Sciences, ZheJiang University, YuHangTang Ave 688, HangZhou, ZheJiang Province, 310058, P. R. China; China Academy of West Region Development, ZheJiang University, YuHangTang Ave 866, HangZhou, 310058, P. R. China

Abstract

Aquaculture industry faces the risk of pathogen infection, leading to economic losses and environmental degradation associated with antibiotic use. Insects, especially black soldier fly larvae (BSFL, Hermetia illucens L.), are considered a promising ingredient in aquafeed due to their abundance of active molecules. In this study, we investigated the effect of incorporating BSFL (raised on domestic biodegradable waste) into the 28-day diets of zebrafish (Danio rerio), containing 0%, 1.5%, 3%, and 10% inclusion levels of full-fat BSFL. Growth performance, immunological parameters, and gene expressions were evaluated. Compared with the control group, BSFL inclusion promoted growth (e.g. specific growth rate increased by 22.4%), while not negatively affecting serum immunity or antioxidant systems of zebrafish. The inclusion of BSFL in diets stimulated the innate immune response of zebrafish (e.g., TNF-α, 32.0%; IL-10, 15%-48%), without inducing chronic inflammation in the intestine. The increase in larvae inclusion tended to increase the transcription levels of genes on igf-1 (growth factor), hsp70.1(stress response), and elovl2 (biosynthesis). This study demonstrates the potential of DBW-derived full-fat BSFL as an aquafeed additive to enhance fish welfare, reduce antibiotic reliance, and contribute to circular economy initiatives.

Keywords