A 10-week feeding trial was conducted to determine the effects of dietary black soldier fly larval meal (BSFLM) on growth performances, digestive enzyme activity, haematological responses and muscle growth-related gene expression of juvenile striped catfish (Pangasianodon hypophthalmus). Six isonitrogenous and isolipidic diets were formulated with BSFLM to replace fishmeal at 0 per cent (T0), 20 per cent (T20), 40 per cent (T40), 60 per cent (T60), 80 per cent (T80) and 100 per cent (T100). A total of 540 fingerlings were randomly distributed into 18 tanks and fed thrice a day. Growth performance and feed utilization of fish fed T20, T40 and T60 diets were not significantly different from T0 diet. However, increasing the percentage of fishmeal replacement with BSFLM to 100% at an inclusion level of 292 g/kg resulted in a substantial reduction in growth and feed efficiency of striped catfish. Fish fed T80 and T100 diets had significantly lower whole-body crude protein, crude lipid, total cholesterol and triglyceride value than fish fed other experimental diets, while dietary inclusion of BSFLM had no significant effect on the whole-body amino acid profile, haematological responses and intestinal and liver protease and amylase activity of striped catfish. However, lipase activity was increased in fish fed T80 and T100 diets. T80 and T100 hepatocytes were shown to have greater congestion in histology than other groups. The relative expression of MyoD and myogenin was significantly maximized in fish fed the T60 diet. Fishmeal may be replaced with BSFLM up to 60 per cent at an inclusion level of 174 g/kg in the diet of juvenile striped catfish.

A 10‐week feeding trial was conducted to evaluate the effects of dietary replacement of fish oil (FO) with black soldier fly larvae oil (BSFLO) and vegetable oils, namely moringa oil (MO), black cumin seed oil (BCSO) and flax seed oil (FSO) on growth and whole‐body fatty acid profile, digestive enzyme activity, haemato‐biochemical responses and muscle growth‐related gene expression of juvenile striped catfish, Pangasianodon hypophthalmus. Five isonitrogenous (313.34 g kg−1) and isolipidic (81.82 g kg−1) experimental diets were formulated. A total of 450 fingerlings (5.02 ± 0.1 g per fish) were randomly distributed into 15 tanks and fed thrice a day. The final weight gain was significantly improved in fish fed FO (45.7 ± 0.72 g/fish), BSFLO (45.53 ± 1.32 g/fish) and MO diet (47.2 ± 0.26 g/fish) when compared to BCSO (36.3 ± 1.05 g/fish) and FSO (35.83 ± 0.71g/ fish) diets. The lower value of daily weight gain was recorded in the FSO and BCSO treatments compared with other oils could be due to effects on stress resistance and immunosuppression in fish, whereas the whole‐body EPA and DHA content of fish fed with FSO and FO diets was substantially higher than fish fed with other experimental diets. However, the relative expression of Myo D and Myogenin was upregulated in fish fed with FO, BSFLO and MO diet than the BCSO and FSO diet. Present results indicate that the juveniles can be reared on diets in which FO has been replaced with BSFLO and MO, with no significant effects on fish performance.