Rapid transgenerational acclimation of a tropical reef fish to climate change

Understanding the capacity of species to acclimate and adapt to expected temperature increases is critical for making predictions about the biological impacts of global warming, yet it is one of the least certain aspects of climate change science(1-4). Tropical species are considered to be especially sensitive to climate change because they live close to their thermal maximum and exhibit limited capacity for acclimation(5-7). Here, we demonstrate that a tropical reef fish is highly sensitive to small increases in water temperature, but can rapidly acclimate over multiple generations. Acute exposure to elevated temperatures (+1.5 degrees C and +3.0 degrees C) predicted to occur this century caused a 15% and 30% respective decrease in individual's maximum ability to perform aerobic activities such as swimming or foraging, known as aerobic scope. However, complete compensation in aerobic scope occurred when both parents and offspring were reared throughout their lives at elevated temperature. Such acclimation could reduce the impact of warming temperatures and allow populations to persist across their current range. This study reveals the importance of transgenerational acclimation as a mechanism for coping with rapid climate change and highlights that single generation studies risk underestimating the potential of species to cope.