Biology of symbiotic dinoflagellates (Symbiodinium) in corals

Abstract

The chapter summarizes the diversity and ecology of zooxanthellae, especially focusing on the dinoflagellate genus Symbiodinium. Symbiodinium spp. are known to engage in mutual symbioses with a wide variety of marine invertebrates (e.g., corals) and protists, in both tropical and temperate waters. Because of an increasing awareness of "coral bleaching" (death of corals due to loss of symbiotic algae), there have been many investigations into Symbiodinium and coral interactions. In this chapter, the taxonomy and general ecology of Symbiodinium are initially described, followed by recent genetic classification systems, which have contributed to a clearer understanding of Symbiodinium diversity and its host specifi city. Finally, mechanisms of both symbiotic initiation and breakdown in association with corals are highlighted, to predict the future of coral reef ecosystems in the changing ocean environments.