Transfer of antibody activity from immunized mother to embryo in tilapias

Antibody activity specific to antigens (PSA, DSA and BGG) which served for immunization of mothers could be measured in extracts of 0‐9‐day‐old embryos spawned by these mothers, using a modified ELISA. The level of antibody activity in embryos varied according to the interval of time between mother immunization and spawning. This activity peaked between 14 and 37 days post‐immunization, then it underwent a significant gradual decrease. The activity of the extract was found to be specific only to the antigen which served for the mother immunization and could be adsorbed only by these antigens. The need of mother immunization against selected pathogens for the prevention of larvae and fry mortality is discussed.