Different algal symbionts explain the vertical distribution of dominant reef corals in the eastern Pacific

Symbiotic reef corals occupy the entire photic zone; however, most species have distinct zonation patterns within the light intensity gradient. It is hypothesized that the presence of specific symbionts adapted to different light regimes may determine the vertical distribution of particular hosts. We have tested this hypothesis by genetic and in situ physiological analyses of the algal populations occupying two dominant eastern Pacific corals, over their vertical distribution in the Gulf of California. Our findings indicate that each coral species hosts a distinct algal taxon adapted to a particular light regime. The differential use of light by specific symbiotic dinoflagellates constitutes an important axis for niche diversification and is sufficient to explain the vertical distribution patterns of these two coral species.

[1]  R. K. Trench,et al.  Acclimation and adaptation to irradiance in symbiotic dinoflagellates. I. Responses of the photosynthetic unit to changes in photon flux density , 1994 .

[2]  A. Baker.  Ecosystems: Reef corals bleach to survive change , 2001, Nature.

[3]  R. Trench.  Specificity in dinomastigote-marine invertebrate symbioses: An evaluation of hypotheses of mechanisms involved in producing specificity , 1988 .

[4]  O. Björkman.  Responses to Different Quantum Flux Densities , 1981 .

[5]  R. Iglesias-Prieto,et al.  Acclimation and adaptation to irradiance in symbiotic dinoflagellates. II. Response of chlorophyll–protein complexes to different photon-flux densities , 1997 .

[6]  H. R. Bonilla.  Effects of the 1997-1998 El Niño-Southern Oscillation on coral communities of the Gulf of California, Mexico , 2001 .

[7]  N. Knowlton,et al.  Landscape ecology of algal symbionts creates variation in episodes of coral bleaching , 1997, Nature.

[8]  R. Buddemeier,et al.  CORAL BLEACHING AS AN ADAPTIVE MECHANISM : A TESTABLE HYPOTHESIS , 1993 .

[9]  D. Powers,et al.  A Molecular Genetic Classification of Zooxanthellae and the Evolution of Animal-Algal Symbioses , 1991, Science.

[10]  P. Falkowski,et al.  Photosynthesis and photoprotection in symbiotic corals , 2001 .

[11]  L. Muscatine,et al.  Reef Corals: Mutualistic Symbioses Adapted to Nutrient-Poor Environments , 1977 .

[12]  J. Jackson.  Adaptation and Diversity of Reef CoralsPatterns result from species differences in resource use and life histories and from disturbances , 1991 .

[13]  J. Felsenstein.  CONFIDENCE LIMITS ON PHYLOGENIES: AN APPROACH USING THE BOOTSTRAP , 1985, Evolution; international journal of organic evolution.

[14]  D. Powers,et al.  Molecular genetic identification of symbiotic dinoflagellates (zooxanthellae) , 1991 .

[15]  N. Huner,et al.  Photosystem II Excitation Pressure and Development of Resistance to Photoinhibition (I. Light-Harvesting Complex II Abundance and Zeaxanthin Content in Chlorella vulgaris) , 1995, Plant physiology.

[16]  A. Baker.  The symbiosis ecology of reef-building corals , 1999 .

[17]  G. Wellington.  Depth Zonation of Corals in the Gulf of Panama: Control and Facilitation by Resident Reef Fishes , 1982 .

[18]  A. Baker.  Flexibility and Specificity in Coral-Algal Symbiosis: Diversity, Ecology, and Biogeography of Symbiodinium , 2003 .

[19]  W. Fitt,et al.  Diurnal changes in photochemical efficiency and xanthophyll concentrations in shallow water reef corals : evidence for photoinhibition and photoprotection , 1999, Coral Reefs.

[20]  Agaricia tenuifolia,et al.  Diversity and community structure of symbiotic dinoflagellates from Caribbean coral reefs , 2002 .

[21]  O. Hoegh‐Guldberg,et al.  Low symbiont diversity in southern Great Barrier Reef corals, relative to those of the Caribbean , 2003 .

[22]  T. G. Owens,et al.  Limitations of the pulse-modulated technique for measuring the fluorescence characteristics of algae. , 1992, Plant physiology.

[23]  Andrés López Pérez,et al.  Biogeogfuphy of the stony corals (scleractinia) of the mexican pacific , 1998 .

[24]  T. Lajeunesse.  INVESTIGATING THE BIODIVERSITY, ECOLOGY, AND PHYLOGENY OF ENDOSYMBIOTIC DINOFLAGELLATES IN THE GENUS SYMBIODINIUM USING THE ITS REGION: IN SEARCH OF A “SPECIES” LEVEL MARKER , 2001 .

[25]  K Maxwell,et al.  Chlorophyll fluorescence--a practical guide. , 2000, Journal of experimental botany.

[26]  P. Davies.  Effect of daylight variations on the energy budgets of shallow-water corals , 1991 .

[27]  T. Lajeunesse,et al.  Biogeography of two species of Symbiodinium (Freudenthal) inhabiting the intertidal sea anemone Anthopleura elegantissima (Brandt). , 2000, The Biological bulletin.

[28]  B. Prézelin,et al.  Mechanisms of photoadaptation in three strains of the symbiotic dinoflagellate Symbiodinium microadriaticum , 1983 .

[29]  J. Connell.  Diversity in tropical rain forests and coral reefs. , 1978, Science.

[30]  G. Schmidt,et al.  High diversity and host specificity observed among symbiotic dinoflagellates in reef coral communities from Hawaii , 2004, Coral Reefs.

[31]  O. Hoegh‐Guldberg,et al.  Photoinhibition and photoprotection in symbiotic dinoflagellates from reef-building corals , 1999 .

[32]  N. Knowlton,et al.  New taxonomy and niche partitioning on coral reefs: jack of all trades or master of some? , 1994, Trends in ecology & evolution.

[33]  P. Glynn.  Some Physical and Biological Determinants of Coral Community Structure in the Eastern Pacific , 1976 .

[34]  N. Knowlton,et al.  Intraspecific diversity and ecological zonation in coral-algal symbiosis. , 1995, Proceedings of the National Academy of Sciences of the United States of America.