Abstract
To investigate the defence mechanisms of the eel Anguilla japonica against Edwardsiella tarda, the chemotactic, phagocytic and bactericidal activities of phagocytes isolated from the posterior kidney of immunized and control eels were examined in the absence of serum. Additionally, the opsonic activity of both immune and control serum was investigated.
Agglutination titers to E.tarda significantly increased 1 to 3 weeks after immunization. In the absence of serum, the chemotactic activity of phagocytes from immunized eels increased 3 weeks after immunization. Phagocytic activity was highest 3 weeks after immunization. Opsonic activity was detected in immune serum. The addition of immune serum increased phagocytic activity, but this increase was reduced by heating of the serum. Bactericidal activity of phagocytes, in the absence of serum, was not enhanced by immunization. It is concluded that immunization of eel enhances the chemotactic and phagocytic activity of phagocytes.
