even at the high water temperature of 25 °C. Oysters in
the 13 °C and 16 °C groups also did not present clinical
signs during the experiment despite having been
exposed. However, in the 19 °C group one oyster had
a coloration level 1 on the 90th day, while in the 22 °C
group one oyster had level 1 on the 60th day, and 50% of
the oysters had level 1 or 2 on the 90th day (Table 2). In
the 25 °C group, 70% of the oysters had coloration level
3 on the 90th day. At even higher temperatures
coloration started earlier and the level is higher. All
oysters in the 31 °C group had the disease on the 60th
day, and 50% of them were of coloration level 3.