Vahid Morshedi

The aim of this study was to investigate the effects of GaroVak immersion vaccine against lactococcosis and streptococcosis disease in different weights on growth and feeding performance and survival rate of Asian Sea bass (Lates calcarifer). Fish with an average weight of 5, 10 and 14 g in 300-liter polyethylene circular tanks in 6 treatments and 2 repetitions including vaccinated groups in low (5 g), medium (10 g) and high-weights (14 g) and control groups of each the weight without vaccination were examined. Feeding was done twice a day ad libitum for 8 weeks. The obtained results showed that GaroVak immersion vaccine has no significant effect on growth performance of fish (P > 0.05). In addition, feeding parameters and survival rate did not show any significant differences between the vaccinated group (ST, MT, LT) and the control group (SC, MC, LC) at the end of the experiment (P > 0.05). However, the result of the bacterial challenge showed that mortality rate in the low-weight vaccinated group (ST) was lower than the medium-weight control group (MC) (P < 0.05). According to the general results of this study, administration of GaroVak immersion vaccine against streptococcosis disease has been able to improve the survival rate after bacterial challenge in low-weight of Asian seabass (5 g).