title: Evidence for Rhythmicity Pacemaker in the Calcification Process of Scleractinian Coral.
abstract: Reef-building scleractinian (stony) corals are among the most efficient bio-mineralizing organisms in nature. The calcification rate of scleractinian corals oscillates under ambient light conditions, with a cyclic, diurnal pattern. A fundamental question is whether this cyclic pattern is controlled by exogenous signals or by an endogenous 'biological-clock' mechanism, or both. To address this problem, we have studied calcification patterns of the Red Sea scleractinian coral Acropora eurystoma with frequent measurements of total alkalinity (AT) under different light conditions. Additionally, skeletal extension and ultra-structure of newly deposited calcium carbonate were elucidated with (86)Sr isotope labeling analysis, combined with NanoSIMS ion microprobe and scanning electron microscope imaging. Our results show that the calcification process persists with its cyclic pattern under constant light conditions while dissolution takes place within one day of constant dark conditions, indicating that an intrinsic, light-entrained mechanism may be involved in controlling the calcification process in photosymbiotic corals.
authors: The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel.
authors: Eldad
authors: E
authors: Gutner-Hoch
authors: The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel.
authors: Kenneth
authors: K
authors: Schneider
authors: Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland.
authors: Jaroslaw
authors: J
authors: Stolarski
authors: MCAM UMR7245, Sorbonne Universités, Muséum National d'Histoire Naturelle, (CP54) 57 rue Cuvier, 75005 Paris, France.
authors: Isabelle
authors: I
authors: Domart-Coulon
authors: Department of Earth and Planetary Sciences, Weizmann Institute of Science, P.O.Box 26, 76100 Rehovot, Israel.
authors: Ruth
authors: R
authors: Yam
authors: Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering (ENAC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.|Center for Advanced Surface Analysis, Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland.
authors: Anders
authors: A
authors: Meibom
authors: Department of Earth and Planetary Sciences, Weizmann Institute of Science, P.O.Box 26, 76100 Rehovot, Israel.
authors: Aldo
authors: A
authors: Shemesh
authors: The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel.
authors: Oren
authors: O
authors: Levy
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000502:physiology*; D001683:Biological Clocks; D002113:Calcification, Physiologic / Q000502:physiology*; D002119:Calcium Carbonate / Q000737:chemistry; D019156:Indian Ocean; D008027:Light; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D018629:Spectrometry, Mass, Secondary Ion; D013325:Strontium Isotopes / Q000737:chemistry
chemical_list: D013325:Strontium Isotopes; D002119:Calcium Carbonate