Stress hardening and acclimatization in Montipora capitata

As ocean temperatures rise phenotypic plasticity will play an increasingly important role in coral health. Using ten genotypes of Montipora capitata, we examined if pre-exposure to thermal stress confers improved performance to a second heat stress ~4 months later. Pre-exposure to a constant 31.5 C elicited a strong gene expression response and improved thermal tolerance by up to two degree heating weeks during subsequent thermal testing. The results show improvements from short-term stress hardening in a reef-building coral and substantial capacity for thermal plasticity.