Antibiotic resistance continues to rise due to frequent and often indiscriminate use of antimicrobial agents. This growing challenge has intensified the need to discover new, safer, and more effective antibiotics. Marine ecosystems and organisms represent rich bioactive compounds that have recently attracted significant research attention. The mucous layer covering fish skin contains numerous antimicrobial factors that serve as the first line of defense against invading pathogens. This study investigated the biological effects of epidermal mucus from Persian Gulf catfish (Arius dussumieri )Following collecting catfish from Bushehr coastal waters and extracting epidermal mucus, bacterial susceptibility testing was performed using the disk diffusion method against various clinical and standard bacterial strains.The proteolytic and hemolytic activities of the epidermal mucus were also examined. Results demonstrated that among Gram-positive bacteria, only Staphylococcus aureus ATCC 6539 showed an inhibition zone in response to the catfish mucus. Among Gram-negative bacteria, inhibition zones were observed solely for Serratia marcescens, Vibrio cholerae, and Salmonella sp..Furthermore, bacteria exposed to the catfish mucus demonstrated reduced capacity for weak biofilm formation. The study confirmed the absence of both proteolytic and hemolytic activity in the epidermal mucus. This research revealed that while catfish mucus can inhibit the growth of certain bacteria and reduce bacterial biofilm formation capacity, its combination with industrial antibiotics may enhance their effectiveness. Evaluation of this compound against pathogenic bacterial and fungal strains in aquatic organisms is recommended, and it may serve as a valuable source of natural antimicrobial compounds for further investigation.