Figure 4

(a–j) Example of medium intestine histomorphology and (k) histological indexes (mucosal folds length, supranuclear vacuoles and Ab+ goblet cell abundance) measured in this gut tract of F1 zebrafish larvae fed diets including 0, 25, 50, 75 and 100% of BSF prepupae meal respect to fish meal (F1Hi0, F1Hi25, F1Hi50, F1Hi75 and F1Hi100 groups). Scale bars and staining: (a–e) 50 μm, H&E; (f–j) 20 μm, Ab. Letters: gc = Ab+ goblet cells. For histological indexes (k), values of mucosal folds length are shown as mean ± standard deviation (n = 15). Scores: supranuclear vacuoles + = scattered, ++ = abundant; Ab+ goblet cells + = 0 to 3 per villus, ++ = 4 to 6 per villus, + + + = more than 6 per villus. No significant differences were detected among the experimental groups.