Seasonal variation in the photo-physiology of homogeneous and heterogeneous Symbiodinium consortia in two scleractinian corals
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Seasonal variation in the photo-physiology of homogeneous and heterogeneous Symbiodinium consortia in two scleractinian corals. / Ulstrup, Karin Elizabeth; Hill, R.; Van Oppen, M. J. H.; Larkum, A. W. D.; Ralph, P. J.
In: Marine Ecology - Progress Series, Vol. 361, 2008, p. 139-150.Research output: Contribution to journal › Journal article › Research › peer-review
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TY - JOUR
T1 - Seasonal variation in the photo-physiology of homogeneous and heterogeneous Symbiodinium consortia in two scleractinian corals
AU - Ulstrup, Karin Elizabeth
AU - Hill, R.
AU - Van Oppen, M. J. H.
AU - Larkum, A. W. D.
AU - Ralph, P. J.
N1 - KEY WORDS: Fast fluorescence kinetics · ITS1 rDNA · LSU rDNA · Symbiodinium · Symbiont density
PY - 2008
Y1 - 2008
N2 - Seasonal variation in the composition of the algal endosymbiont community and photo-physiology was determined in the corals Pocillopora damicornis, which show high local fidelity to one symbiont type (Symbiodinium C1), and Acropora valida, with a mixed Symbiodinium symbiont community, comprising members of both clades A and C. The relative abundances of Symbiodinium types varied over time. A significant decline in symbiont densities in both coral species during the summer of 2005 coincided with a NOAA ‘hotspot' warning for Heron Island. This also coincided with a relative increase in the presence and dominance of clade A in A. valida, particularly in sun-adapted surfaces. The effective quantum yield of Photosystem II (FPSII) suggested that sun-adapted surfaces of P. damicornis are more sensitive than shade-adapted surfaces to combined effects of higher temperature and irradiance in summer. Xanthophyll cycling was greater in P. damicornis than A. valida, irrespective of branch position and sampling time; this may be a mechanism by which P. damicornis compensates for its fidelity to Symbiodinium C1. Furthermore, xanthophyll de-epoxidation in P. damicornis symbionts was greater in sun-adapted than shade-adapted surfaces, correlating with non-photochemical quenching (NPQRLC). No variation was found in A. valida, indicating that resident symbiont communities may not have been physiologically compromised, perhaps as a result of changes in the composition of the Symbiodinium community consortia.
AB - Seasonal variation in the composition of the algal endosymbiont community and photo-physiology was determined in the corals Pocillopora damicornis, which show high local fidelity to one symbiont type (Symbiodinium C1), and Acropora valida, with a mixed Symbiodinium symbiont community, comprising members of both clades A and C. The relative abundances of Symbiodinium types varied over time. A significant decline in symbiont densities in both coral species during the summer of 2005 coincided with a NOAA ‘hotspot' warning for Heron Island. This also coincided with a relative increase in the presence and dominance of clade A in A. valida, particularly in sun-adapted surfaces. The effective quantum yield of Photosystem II (FPSII) suggested that sun-adapted surfaces of P. damicornis are more sensitive than shade-adapted surfaces to combined effects of higher temperature and irradiance in summer. Xanthophyll cycling was greater in P. damicornis than A. valida, irrespective of branch position and sampling time; this may be a mechanism by which P. damicornis compensates for its fidelity to Symbiodinium C1. Furthermore, xanthophyll de-epoxidation in P. damicornis symbionts was greater in sun-adapted than shade-adapted surfaces, correlating with non-photochemical quenching (NPQRLC). No variation was found in A. valida, indicating that resident symbiont communities may not have been physiologically compromised, perhaps as a result of changes in the composition of the Symbiodinium community consortia.
U2 - 10.3354/meps07360
DO - 10.3354/meps07360
M3 - Journal article
VL - 361
SP - 139
EP - 150
JO - Marine Ecology - Progress Series
JF - Marine Ecology - Progress Series
SN - 0171-8630
ER -
ID: 10095780