CS12 Coral Reefs
Date: Wednesday, June 12, 2002
Time: 4:30:00 PM
Location: Colwood
 
WarnerME, University of Delaware, College of Marine Studies, Lewes, USA, mwarner@udel.edu
Baker, A, C, Wildlife Conservation Society, New York, USA, abaker@wcs.org
LaJeunesse, T, C, University of Georgia, Department of Botany, Athens, USA, lajeunes@dogwood.botany.uga.edu
 
COMBINING PHYSIOLOGY WITH PHYLOGENY TO UNDERSTAND ECOLOGICAL DISTRIBUTIONS OF SYMBIOTIC DINOFLAGELLATES
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Roughly 25% of scleractinan corals may harbor more than one type of symbiotic dinoflagellate of the genus Symbiodinium, known by the generic name zooxanthellae. There appear to be strong correlations between the ecological distribution of some polymorphic symbioses and physical gradients (e.g. light and/or temperature) yet the physiological mechanisms that may be driving such correlations remain largely unexplored. Furthermore, it remains unclear if related symbiont taxa have similar physiological constraints that may correspond to phylogenetic groupings. A survey of several species of reef building corals, both known to historically maintain single as well as multiple dinoflagellate types, was conducted on Glovers Reef in Belize from a depth of 30 to 6 meters. Photosynthesis was monitored by in situ chlorophyll fluorescence analysis and the maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield, and the reduction state of the primary quinone electron charge acceptor of PS II, QA, were recorded. These data were combined with genetic characterizations using analyses of both genes to the LSU rRNA and the internal transcribed spacer region 2 (ITS 2) in order to discern how algal distributions may be modeled by physiological factors.