Acclimation period affects tissue condition in the Caribbean staghorn coral, Acropora cervicornis

Many published coral disease pathogen transmission and heat stress studies lack consistent acclimation periods in their experimental design, making it difficult to interpret or compare results between studies. To determine if condition of coral tissue changes during laboratory acclimation, thus potentially influencing susceptibility to stressors, we conducted a histological analysis on fragments of the Caribbean staghorn coral, Acropora cervicornis, during a 9-day acclimation period. We found a significant decline in overall condition between clippings taken initially and on day 2, and significant improvements in two key surface body wall parameters from day 2 to day 9. These findings indicate that A. cervicornis has a delayed response to new environmental conditions and therefore needs at least a 4-day acclimation period, and when possible, 9 days or more prior to experimentation.