A coral bleaching hypothesis wherein under changing environmental conditions, the loss of one or more kinds of zooxanthellae is rapidly followed by the formation of new symbiotic cnidarian-algal relationships with different zooxanthellae that are more suited to the new conditions in the host's habitat. Fundamental assumptions of the ABH include (1) different types of zooxanthellae respond differently to environmental conditions, specifically temperature, and (2) bleached adults can secondarily acquire zooxanthellae from the environment.