But only up to a point. After all, too much of a good thing becomes bad. While from black soldier fly larvae are often valuable diet components, they cannot comprise the entire diet.

Chang, T., Lin, H., Han, F., Xu, C. and Li, E., 2024. Impact of defatted black soldier fly (Hermetia illucens) larvae meal on health, muscle texture, and intestinal microbiota in Pacific white shrimp (Penaeus vannamei). Aquaculture, 741755. https://doi.org/10.1016/j.aquaculture.2024.741755

Defatted black soldier fly larvae meal is a highly promising substitute for fishmeal, with its impact on gut health and muscle quality in Pacific white shrimp (Penaeus vannamei) being crucial for its further development and utilization. This study conducted an 8-week feeding trial to evaluate the effects of replacing fishmeal with defatted black soldier fly (Hermetia illucens) larvae meal (DBSFLM) on the growth, muscle texture, and gut health of P. vannamei. Six isonitrogenous and isolipidic diets were formulated, with DBSFLM added at levels of 0 %, 4.12 %, 8.24 %, 12.36 %, 16.48 %, and 20.61 % to replace different proportions of fishmeal. The results showed that adding up to 20.61 % DBSFLM to replace 75 % of fishmeal did not significantly affect shrimp growth performance. The optimal inclusion level of DBSFLM is 4.12 % to 8.24 %, which not only reduces intestinal inflammation and enhances gut microbiota interactions but also improves muscle texture and flavor, while boosting immunity and antioxidant capacity. However, adding more than 16.48 % DBSFLM leads to intestinal inflammation and hepatocellular damage, and negatively affects muscle texture and amino acid composition. Overall, while adding up to 20.61 % DBSFLM (to replace 75 % of fishmeal) does not affect shrimp growth, an inclusion level of no more than 12.36 % (to replace 45 % of fishmeal) is recommended for optimal flavor and health.

Zheng, J.Y., Gan, Z.R., Huang, T.Y., Xiao, Y., Xu, W.Y., Li, X.Q. and Leng, X.J., 2024. Replacement of fish meal with defatted black soldier fly (Hermetia illucens) in diet of Pacific white shrimp (Litopenaeus vannamei): growth, flesh quality and transcriptome. Journal of Insects as Food and Feed, https://doi.org/10.1163/23524588-00001235

This study evaluated the impacts of replacing fish meal (FM) with defatted black soldier fly (Hermetia illucens; BSF) on the growth performance, flesh quality and transcriptome of Pacific white shrimp (Litopenaeus vannamei). In a diet containing 560 g/kg FM, BSF was used to replace 0%, 20%, 40%, 60%, 80% and 100% of dietary FM (BSF0, BSF20, BSF40, BSF60, BSF80 and BSF100). Thus, six isonitrogenous and isolipidic diets were prepared, and then fed to juvenile Pacific white shrimp (1.70 ± 0.10 g) for 60 days. In growth performance, the BSF20 group showed the similar FCR and WGR to the control group ( P > 0.05), and the other four BSF groups presented significantly lower WGR and higher FCR than the BSF0 group ( P < 0.05). The flesh chewiness and the contents of crude lipid, collagen and total amino acid in flesh were significantly decreased ( P < 0.05), and flesh cooking loss, thawing loss was significantly increased when the replaced FM was ≥40% ( P < 0.05). When the replaced FM reached 60%, the flesh hardness, heat-insoluble collagen content, shear force, body surface redness and the ratio of n-3/n-6 fatty acids were significantly lower ( P < 0.05), while n-6 polyunsaturated fatty acid content and total free amino acid content in flesh were significantly higher than those of the BSF0 group ( P < 0.05). Hepopancreatic samples were used for transcriptomic analysis, and a total of 1,456 differentially expressed genes (DEGs) were identified between the BSF groups and BSF0 group, which were mainly involved in growth-promoting, energy metabolism and antioxidant capacity key pathways and genes, including the cathepsin L, folate synthesis pathway, redox-related genes and glutathione metabolism pathway. In conclusion, in a diet containing 560 g/kg FM, BSF could successfully replace 20% of dietary FM, and higher FM replacement (≥40%) decreased the growth performance and flesh quality of Pacific white shrimp.