SICB Division of Ecology and Evolution (DEE)

DEE Researchers Database Entry

Mary Alice Coffroth

Population dynamics and early ontogeny of the symbiosis between the dinoflagellate and cnidarian hosts such as coral
My research examines the population dynamics and early ontogeny of the symbiosis between the dinoflagellate Symbiodinium spp. (inset A) and cnidarian hosts such as coral. My current work focuses on understanding variation among Symbiodinium populations in both newly-settled (primary) polyps and in adult hosts, and characterizing the variation within a single host colony, within a host genotype and across the host population. Most cnidarian-microalgae symbioses exhibit some degree of specificity in host-symbiont pairing, but the level of specificity and the mechanisms by which it is achieved are not clear. By defining the population structure of zooxanthellae within an individual host and among the host population and detailing the early stages of this symbiosis, we are identifying the level of host specificity of zooxanthellae symbiotic within a number of Caribbean octocorals and the dynamics of these symbioses. The dendrogram above shows the relationships between symbiont populations of the octocoral Pseudopterogorgia elisabethae (inset B) at 12 sites in the Bahamas. Knowledge of how Symbiodinium populations within scleractinians and octocorals are established and understanding how flexible these symbioses are in response to environmental perturbations is essential to understanding host and symbiont distribution patterns, and the processes that are critical to maintaining a viable symbiosis. Phenomena such as coral bleaching (the loss of algal symbionts or algal pigments) and the effects of global climate change on reef corals are fundamentally questions about the interaction of host and symbiont, and the studies we are conducting are crucial to our understanding of these larger questions.