This study investigated the effects of fish swimming bladder oligopeptides (FSBO) at varying concentrations (5,10,and 20 g/L) on tyrosinase (TYR) activity,cyclic adenosine monophosphate (cAMP) levels,and melanin content in mouse melanoma cells B16.Additionally,the melanogenesis-inhibitory effects of 10 g/L FSBO,cod collagen peptides (CCP),and vitamin C (V_C) were compared.Furthermore,optimal concentrations of FSBO,CCP and V_C for reducing melanin content in B16 cells were screened.The results demonstrated that treatment with 5,10,and 20 g/L FSBO for 24 h significantly suppressed TYR activity and reduced both cAMP and melanin levels in B16 cells.At 10 g/L,the inhibitory efficacy on TYR activity and cAMP content followed the order:V_C > CCP > FSBO,while melanin reduction efficacy ranked CCP > FSBO = V_C.Notably,melanin content progressively increased with higher concentrations (1.25,2.5,10 g/L) of V_C and FSBO,but decreased in the CCP -treated group.Both 1.25 g/L and 2.5 g/L FSBO,as well as 10 g/L CCP,exhibited comparable melanin-reducing effects to V_C.These findings indicate that FSBO and CCP,two fish-derived bioactive peptides,effectively inhibit melanogenesis by downregulating TYR activity and cAMP levels,albeit with distinct concentration-dependent responses.This study expands the understanding of the skincare potential and mechanisms of bioactive peptides,providing a theoretical foundation for the application of marine peptide derivatives in cosmetic formulations.