Probiotics have been increasingly used in aquaculture to improve gut and overall health of fish and shrimp, as well as to provide optimal water quality by removing toxic metabolites. However, fish and shrimp are farmed under wide range of temperature and salinity conditions, which can influence the efficacy of probiotic strains. The objectives of the present study were to evaluate (i) the effects of temperature (15 and 27C), pH (2, 3, 5, 7 and 8) and salinity (0 and 20 ppt) on the germination and growth of Bacillus amyloliquefaciens CECT 5940 (Ecobiol®) under in-vitro conditions, (ii) the time it takes for the in vitro germination and growth of B. amyloliquefaciens spores under optimal growing conditions, and (iii) the bacteriostatic activity of B. amyloliquefaciens probiotics against various common fish and shrimp pathogens. The bacteria grew better at 27 °C versus 15 °C with recorded growth being 9.05E+08 and 7.20E+06 cfu/ml, respectively. However, between 0 and 20 ppt salinity, bacterial growth did not differ significantly with the recorded growth being 8.8E+08 and 9.5E+08 cfu/ml, respectively. Among the pH values tested (2, 3, 5, 7, and 8), B. amyolliquefaceans did not grow at pH 2 and 3. However, at pH 5, 7 and 8, they grew increasingly well with increasing pH: values of germinated spores were 8.09E+08, 8.9E+08, and 1.01E +09 cfu/ml at the pH 5, 7 and 8, respectively. The evaluation of the kinetics of growth provided evidence that B. amyloliquefaciens spores seeded in culture medium at the start of the experiment were mostly germinated in 1 hour under optimal growing conditions. This suggests that B. amyloliquefaciens can start acting in the digestive system of the target species in a rather short time. Bacteriostatic activity measured by zone of inhibition test showed that B. amyloliqufaciens inhibits the growth of various fish and shrimp pathogens including Vibrio parahaemolyticus, V. penaecida, V. alginolyticus, V. harveyi, V. anguilarum, Streptococcus agalactiae, S. iniae, Aeromonas hydrophila. Our study provided key evidences that Bacillus amyloliquefaciens CECT 5940can be used in aquaculture under a wide range of culture conditions to control common fish and shrimp pathogens.