Abstract
A bath challenge method with Tenacibaculumi maritimum was examined using juvenile Japanese flounder Paralichthys olivaceus. After immersed in the bacterial suspensions at different concentrations for 1 h, fish were maintained at 15°C, 20°C and 25°C. At any temperatures, mortalities were 80-100% and 20-40% in fish challenged at 107.9 and 106.9 CFU/mL, respectively. No disease signs were observed in fish challenged at 105.9 CFU/mL. The affected fish exhibited mouth reddening and skin erosion, and T. maritimum were re-isolated from the hemorrhagic skin lesions. The seed lot method used in the present study probably provided reproducible results with high mortality.
