Nanopeptide C-I20 remarkably enhances growth performance and disease resistances by improving the mucosal structure, antioxidant capacity, and immunity in mandarin fish (Siniperca chuatsi)

Soybean meal, excessively used in place of fish meal (FM) in aquaculture, has a detrimental impact on fish. In this study, the nanopeptide C-I20, which was created by conjugating antimicrobial peptide gcIFN-20H and CMCS, were evaluated the feeding effect in mandarin fish (Siniperca chuatsi). Compared with the control group, 150 mg/ kg C-I20-fed fish showed the second highest growth performance with no significant changes in body composition. C-I20-fed fish showed more goblet cells and thicker mucin after feeding. The 150 mg/kg C-I20 diet boosted the antioxidant capacity, immunity, and digestive enzymes. After Aeromonas hydrophila and infection spleen and kidney necrosis virus infection, the survival rates in the 150 mg/kg C-I20 group were highest. Meanwhile, many tissues in the 150 mg/kg C-I20 group had significantly lower pathogen loads than the other groups. Treatment with 150 mg/kg C-I20 was effective in increasing antioxidant capacity and immunity. The minimum tissue lesions were observed in the 150 mg/kg C-I20 group. The goblet cell number and mucin thickness were significantly increased by C-I20 treatment after infection. The study results herein showed that a reasonable dietary concentration of C-I20 feed promoted growth performance and disease resistances in fish, suggesting a prospective nano antimicrobial peptide for the aquaculture.