Meeting Abstract

2.8  Saturday, Jan. 4 09:30  Partner specificity precedes environmental zonation in coral-algal symbioses LEWIS, A.M.*; WHAM, D.C.; LAJEUNESSE, T.C.; The Pennsylvania State Univ.; The Pennsylvania State Univ.; The Pennsylvania State Univ. allisonlewis@psu.edu

It has been nearly two decades since the first account of the environmentally regulated patterning of microalgae (genus Symbiodinium) associated with the western Atlantic corals Orbicella (=Montastraea). This early revelation suggested that coral-algal symbioses might be highly dynamic, responding to environmental fluctuation by changing resident symbiont populations. Recently developed high-resolution genetic markers expand our ability to define species boundaries among morphologically nondescript Symbiodinium and identify individual genotypes through phylogenetic and population genetic analyses. These data obtained from a broad range of host sources indicates that Symbiodinium common to Orbicella are host-specific and distinct from the many species of Symbiodinium found in other cnidarians in the immediate environment. Furthermore, while many Orbicella at shallow and intermediate depths harbor multiple (2-3) Symbiodinium species, each resident species comprises a monoclonal population. Our results suggest that high specificity exists between species of coral host and symbiont.