The kinetics of antibody titers and degree of protection in Indian major carps, catla (Catla catla) and rohu (Labeo rohita) against Aeromonas hydrophila antigen were studied in details at four different age groups of 120, 150, 210 and 270 days old. The first injection () was given with ml of 108 cells/fish of A. hydrophila antigen. The second injection was given on 20 days after the first injection with same dose. The peak antibody titer was observed on day 14 after first injection and on day 7 after second injection in all the age groups of both the species. | Kinetics of antibody titers and degree of protection in Indian Major Carps Catla Catla catla and Rohu Labeo rohita to Aeromonas hydrophila Antigen