Comparing black soldier fly (Hermetia illucens) larvae versus prepupae in the diets of largemouth bass, Micropterus salmoides: Effects on their growth, biochemical composition, histopathology, and gene expression

A feeding trial was performed to compare the supplementation of full-fat black soldier fly, Hermetia illucens, larvae -BSFL versus pre-pupae -BSFP in the diets of largemouth bass, Micropterus salmoides, juveniles. Both BSFL and BSFP were produced in the laboratory from the same batch and ingredients although BSFP tended to have higher protein and amino acid content. Four isonitrogenous and isolipidic diets were formulated including a fishmeal-based control diet -D1, soybean meal-based diet -D2 and soybean meal-based diets with either BSFL -D3 or BSFP-D4 contributing protein. Survival, growth, feed intake, muscle/liver fatty acid composition/mineral composition, hepatic/intestinal expression of growth (insulin-like growth factor , growth hormone GH, lipid metabolism -cholesterol 7 alpha-hydroxylase CYP7A1, fatty acid synthase FASN, antioxidant sentinals superoxide dismutase SOD, inflammatory cytokines -tumor necrosis factor transforming growth factor representative genes as well as liver/intestinal histopathology were determined.