Effect of water temperature on a herpesvirus infection of sea turtles

The role of water temperature in the induction and maintenance of a dermal herpesvirus infection (gray-patch disease) of young, green sea turtles (Chelonia mydas) was studied under carefully controlled experimental conditions, in which the influence of other recognized stress factors was negligible. A nimals that were subjected to a gradual temperature increase from 25 to 30 degrees C, with subsequent maintenance at 30 degrees C, and those that were abruptly shifted from water at 25 degrees C to water at 30 degrees C showed a significantly shorter period before the onset of clinical signs and an increase in the severity of the lesions when compared with control animals. Animals that were subjected to a gradual increase in water temperature from 25 to 30 degrees C and a subsequent decrease to 25 degrees C, where they were maintained, had a period before onset of clinical signs and severity closer to that of control animals. Our findings indicate that both the induction of clinical gray-patch disease and the severity of the lesions are affected by water temperature and suggest that one possible means of control of this herpesvirus infection under intensive aquaculture conditions might be water temperature manipulation.