Study on black soldier fly larvae (Hermetia illucens) diet impact on snubnose pompano’s (Trachinotus blochii) growth and skin mucus immunity

Abstract Utilizing black soldier fly larvae (BSFL, Hermetia illucens ) as an alternative protein source to replace fishmeal (FM) in aquaculture feeds is gaining popularity. This research assessed the effects of various BSFL inclusion levels (0, 25, 50 and 100%) in commercial fish feeds on the growth performance and skin mucus immunity of snubnose pompano ( Trachinotus blochii ). In the study, 30 snubnose pompano (2.669 ± 0.219 cm in total length) were divided into triplicate groups and raised in 20-litre tanks, each fed with different diets. After a four-week feeding trial, body parameters were measured for 10 fish per tank, and skin mucus samples were collected for lysozyme assay. The results showed that up to 50% BSFL inclusion had no significant impact ( ) on fish growth (final body weight and length, percentage weight gain and length gain, specific growth rate, condition factor). However, the 100% BSFL diet adversely affected fish growth, resulting in the lowest performance among the treatments. Diets with 0%, 25%, and 50% BSFL showed significantly higher feed conversion efficiency and lower feed conversion ratio ( ) compared to the 100% BSFL diet. Consequently, the 100% BSFL diet treatment incurred significantly higher feed costs than diets containing up to 50% BSFL. The survival rate and skin mucus immunity of snubnose pompano were not significantly influenced by any level of BSFL inclusion ( ). These findings suggest that BSFL can be effectively included up to 50% in snubnose pompano diets without compromising growth performance and fish immunity.