The portal of entry for pathogenic Vibrio alginolyticus into large yellow croaker Pseudosciaena crocea is via the intestinal tract rather than gill or skin according to the kinetics of the bacterial adhesion to different mucus. The different effects on adhesion caused by proteolytic enzymes and heat treatment might be due to the different chemical compositions of mucus. Adhesion of V. alginolyticus to mucus depends on concerted action of bacterial surface structures such as cell-surface proteins, somatic antigens, flagella, etc. In addition, starvation and monosaccharides, especially fructose, inhibit the bacterial adhesion to the mucus. Knowledge of these adhesive characteristics should be very useful for designing more efficacious prophylactic strategies.