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Meeting Abstract
Coral bleaching involves the loss of essential, photosynthetic dinoflagellates (Symbiodinium sp.) from host gastrodermal cells and occurs as a stress response of both members of the symbiosis. Although a variety of cellular bleaching mechanisms have been proposed, the histological organization of healthy symbiotic cnidarian tissues remains largely undescribed. Thus, a detailed ultrastructural analysis of a commonly used model symbiotic cnidarian is critical in order to provide essential baseline information for future bleaching investigations to assess cellular changes in response to stress conditions. In this study, both transmission electron microscopy (TEM) and fluorescence microscopy (FM) were used to examine and characterize multiple regions throughout the tentacles of both symbiotic and aposymbiotic A. pallida. This study represents the first detailed and systematic histological analysis of the Aiptasia-Symbiodinium model system or that of any other symbiotic cnidarian. Moreover, the ultrastructural information gained from this analysis can be used as an informative health assessment tool as they are manipulated in the lab or during field-mediated conditions.