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Moynihan MA, Amini S, Oalmann J, Chua JQI, Tanzil JTI, Fan TY, Miserez A, Goodkin NF. Crystal orientation mapping and microindentation reveal anisotropy in Porites skeletons. Acta Biomater 2022; 151:446-456. [PMID: 35963519 DOI: 10.1016/j.actbio.2022.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 11/28/2022]
Abstract
Structures made by scleractinian corals support diverse ocean ecosystems. Despite the importance of coral skeletons and their predicted vulnerability to climate change, few studies have examined the mechanical and crystallographic properties of coral skeletons at the micro- and nano-scales. Here, we investigated the interplay of crystallographic and microarchitectural organization with mechanical anisotropy within Porites skeletons by measuring Young's modulus and hardness along surfaces transverse and longitudinal to the primary coral growth direction. We observed micro-scale anisotropy, where the transverse surface had greater Young's modulus and hardness by ∼ 6 GPa and 0.2 GPa, respectively. Electron backscatter diffraction (EBSD) revealed that this surface also had a higher percentage of crystals oriented with the a-axis between ± 30-60∘, relative to the longitudinal surface, and a broader grain size distribution. Within a region containing a sharp microscale gradient in Young's modulus, nanoscale indentation mapping, energy dispersive spectroscopy (EDS), EBSD, and Raman crystallography were performed. A correlative trend showed higher Young's modulus and hardness in regions with individual crystal bases (c-axis) facing upward, and in crystal fibers relative to centers of calcification. These relationships highlight the difference in mechanical properties between scales (i.e. crystals, crystal bundles, grains). Observations of crystal orientation and mechanical properties suggest that anisotropy is driven by microscale organization and crystal packing, rather than intrinsic crystal anisotropy. In comparison with previous observations of nanoscale isotropy in corals, our results illustrate the role of hierarchical architecture in coral skeletons and the influence of biotic and abiotic factors on mechanical properties at different scales. STATEMENT OF SIGNIFICANCE: Coral biomineralization and the ability of corals' skeletal structure to withstand biotic and abiotic forces underpins the success of reef ecosystems. At the microscale, we show increased skeletal stiffness and hardness perpendicular to the coral growth direction. By comparing nano- and micro-scale indentation results, we also reveal an effect of hierarchical architecture on the mechanical properties of coral skeletons and hypothesize that crystal packing and orientation result in microscale anisotropy. In contrast to previous findings, we demonstrate that mechanical and crystallographic properties of coral skeletons can vary between surface planes, within surface planes, and at different analytical scales. These results improve our understanding of biomineralization and the effects of scale and direction on how biomineral structures respond to environmental stimuli.
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Affiliation(s)
- Molly A Moynihan
- Earth Observatory of Singapore, Interdisciplinary Graduate School, Nanyang Technological University, Singapore, Singapore; Asian School of the Environment, Nanyang Technological University, Singapore, Singapore; Marine Biological Laboratory, Woods Hole, MA, USA.
| | - Shahrouz Amini
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore; Max Planck Institute of Colloids and Interfaces, Department of Biomaterials, Potsdam, Germany
| | - Jeffrey Oalmann
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore
| | - J Q Isaiah Chua
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore
| | - Jani T I Tanzil
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore; St. John's Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, 18 Kent Ridge Road, 119227, Singapore
| | - T Y Fan
- National Museum of Marine Biology and Aquarium, Pingtung, Taiwan
| | - Ali Miserez
- Center for Biomimetic Sensor Science, School of Materials Science & Engineering, Nanyang Technological University, Singapore, Singapore; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Nathalie F Goodkin
- Earth Observatory of Singapore, Nanyang Technological University, Singapore, Singapore; American Museum of Natural History, New York, NY, USA
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Dellaert Z, Vargas PA, La Riviere PJ, Roberson LM. Uncovering the Effects of Symbiosis and Temperature on Coral Calcification. THE BIOLOGICAL BULLETIN 2022; 242:62-73. [PMID: 35245159 DOI: 10.1086/716711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
AbstractWe tested the impact of temperature and symbiont state on calcification in corals, using the facultatively symbiotic coral Astrangia poculata as a model system. Symbiotic and aposymbiotic colonies of A. poculata were reared in 15, 20, and 27 °C conditions. We used scanning electron microscopy to quantify how these physiological and environmental conditions impact skeletal structure. Buoyant weight data over time revealed that temperature significantly affects calcification rates. Scanning electron microscopy of A. poculata skeletons showed that aposymbiotic colonies appear to have a lower density of calcium carbonate in actively growing septal spines. We describe a novel approach to analyze the roughness and texture of scanning electron microscopy images. Quantitative analysis of the roughness of septal spines revealed that aposymbiotic colonies have a rougher surface than symbiotic colonies in tropical conditions (27 °C). This trend reversed at 15 °C, a temperature at which the symbionts of A. poculata may exhibit parasitic properties. Analysis of surface texture patterns showed that temperature impacts the spatial variance of crystals on the spine surface. Few published studies have examined the skeleton of A. poculata by using scanning electron microscopy. Our approach provides a way to study detailed changes in skeletal microstructure in response to environmental parameters and can serve as a proxy for more expensive and time-consuming analyses. Utilizing a facultatively symbiotic coral that is native to both temperate and tropical regions provides new insights into the impact of both symbiosis and temperature on calcification in corals.
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Drake JL, Mass T, Stolarski J, Von Euw S, van de Schootbrugge B, Falkowski PG. How corals made rocks through the ages. GLOBAL CHANGE BIOLOGY 2020; 26:31-53. [PMID: 31696576 PMCID: PMC6942544 DOI: 10.1111/gcb.14912] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/28/2019] [Accepted: 10/30/2019] [Indexed: 05/03/2023]
Abstract
Hard, or stony, corals make rocks that can, on geological time scales, lead to the formation of massive reefs in shallow tropical and subtropical seas. In both historical and contemporary oceans, reef-building corals retain information about the marine environment in their skeletons, which is an organic-inorganic composite material. The elemental and isotopic composition of their skeletons is frequently used to reconstruct the environmental history of Earth's oceans over time, including temperature, pH, and salinity. Interpretation of this information requires knowledge of how the organisms formed their skeletons. The basic mechanism of formation of calcium carbonate skeleton in stony corals has been studied for decades. While some researchers consider coral skeletons as mainly passive recorders of ocean conditions, it has become increasingly clear that biological processes play key roles in the biomineralization mechanism. Understanding the role of the animal in living stony coral biomineralization and how it evolved has profound implications for interpreting environmental signatures in fossil corals to understand past ocean conditions. Here we review historical hypotheses and discuss the present understanding of how corals evolved and how their skeletons changed over geological time. We specifically explain how biological processes, particularly those occurring at the subcellular level, critically control the formation of calcium carbonate structures. We examine the different models that address the current debate including the tissue-skeleton interface, skeletal organic matrix, and biomineralization pathways. Finally, we consider how understanding the biological control of coral biomineralization is critical to informing future models of coral vulnerability to inevitable global change, particularly increasing ocean acidification.
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Affiliation(s)
- Jeana L Drake
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, USA
| | - Tali Mass
- Department of Marine Biology, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
| | | | - Stanislas Von Euw
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | | | - Paul G Falkowski
- Department of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
- Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ, USA
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D'Olivo JP, McCulloch MT. Response of coral calcification and calcifying fluid composition to thermally induced bleaching stress. Sci Rep 2017; 7:2207. [PMID: 28526853 PMCID: PMC5438395 DOI: 10.1038/s41598-017-02306-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/10/2017] [Indexed: 01/14/2023] Open
Abstract
Severe, global-scale thermal stress events like those of 1998 and 2016, are becoming more frequent and intense, potentially compromising the future of coral reefs. Here we report the effects of the 1998 bleaching event on coral calcification as well as the composition of the calcifying fluid (cf) from which corals precipitate their calcium carbonate skeletons. This was investigated by using the Sr/Ca, Li/Mg (temperature), and boron isotopes (δ11B) and B/Ca (carbonate chemistry) proxies in a Porites sp. coral. Following the summer of 1998 the coral exhibited a prolonged period (~18 months) of reduced calcification (~60%) and a breakdown in the seasonality of the geochemical proxies. However, the maintenance of elevated dissolved inorganic carbon (DICcf; >×2 seawater) and pHcf (>8.3 compared to seawater ~8.0) even during severe stress of 1998 indicate that a minimum threshold of high aragonite saturation state (Ωcf) of ~14 (~×4 seawater), is an essential pre-requisite for coral calcification. However, despite maintaining elevated levels of Ωcf even under severe stress, coral growth is still impaired. We attribute this to reductions in either the effective active volume of calcification and/or DICcf as bleaching compromises the photosynthetically fixed carbon pool available to the coral.
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Affiliation(s)
- J P D'Olivo
- ARC Centre of Excellence for Coral Reefs Studies, Oceans Institute and School of Earth Sciences, The University of Western Australia, Crawley, 6009, Australia.
| | - M T McCulloch
- ARC Centre of Excellence for Coral Reefs Studies, Oceans Institute and School of Earth Sciences, The University of Western Australia, Crawley, 6009, Australia
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Saha N, Webb GE, Zhao JX. Coral skeletal geochemistry as a monitor of inshore water quality. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 566-567:652-684. [PMID: 27239711 DOI: 10.1016/j.scitotenv.2016.05.066] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 05/10/2016] [Accepted: 05/10/2016] [Indexed: 06/05/2023]
Abstract
Coral reefs maintain extraordinary biodiversity and provide protection from tsunamis and storm surge, but inshore coral reef health is degrading in many regions due to deteriorating water quality. Deconvolving natural and anthropogenic changes to water quality is hampered by the lack of long term, dated water quality data but such records are required for forward modelling of reef health to aid their management. Reef corals provide an excellent archive of high resolution geochemical (trace element) proxies that can span hundreds of years and potentially provide records used through the Holocene. Hence, geochemical proxies in corals hold great promise for understanding changes in ancient water quality that can inform broader oceanographic and climatic changes in a given region. This article reviews and highlights the use of coral-based trace metal archives, including metal transported from rivers to the ocean, incorporation of trace metals into coral skeletons and the current 'state of the art' in utilizing coral trace metal proxies as tools for monitoring various types of local and regional source-specific pollution (river discharge, land use changes, dredging and dumping, mining, oil spills, antifouling paints, atmospheric sources, sewage). The three most commonly used coral trace element proxies (i.e., Ba/Ca, Mn/Ca, and Y/Ca) are closely associated with river runoff in the Great Barrier Reef, but considerable uncertainty remains regarding their complex biogeochemical cycling and controlling mechanisms. However, coral-based water quality reconstructions have suffered from a lack of understanding of so-called vital effects and early marine diagenesis. The main challenge is to identify and eliminate the influence of extraneous local factors in order to allow accurate water quality reconstructions and to develop alternate proxies to monitor water pollution. Rare earth elements have great potential as they are self-referencing and reflect basic terrestrial input.
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Affiliation(s)
- Narottam Saha
- School of Earth Sciences, The University of Queensland, QLD 4072, Australia.
| | - Gregory E Webb
- School of Earth Sciences, The University of Queensland, QLD 4072, Australia
| | - Jian-Xin Zhao
- School of Earth Sciences, The University of Queensland, QLD 4072, Australia
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Coronado I, Pérez-Huerta A, Rodríguez S. Analogous biomineralization processes between the fossil coral Calceola sandalina (Rugosa, Devonian) and other Recent and fossil cnidarians. J Struct Biol 2016; 196:173-186. [PMID: 27327265 DOI: 10.1016/j.jsb.2016.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 06/12/2016] [Accepted: 06/17/2016] [Indexed: 11/18/2022]
Abstract
The current work represents a distinctive study about the biomineral properties of exceptionally good preserved skeletons of Calceola sandalina from the Middle Devonian of Couvin (Belgium), Smara (Morocco) and (Algeria) and their relation in the evolution of biomineralization of cnidarians. Structural and crystallographic analyses of the skeletons have been done by petrographic microscopy, electron scanning microscopy (SEM), atomic force microscopy (AFM), electron backscatter diffraction (EBSD), computer-integrated polarization microscopy (CIP) and electron microprobe analysis (EMPA). Calceola skeletons have many similarities with other cnidarians, mainly with other Palaeozoic corals as Syringoporicae: The microcrystals are composed of co-oriented nanocrystals that remind to mesocrystals, suggesting a biocrystallization process by particle attachment (CPA). The relationship between the nanocrystals and microcrystals suggest a growth mode similar to mineral bridges. A similar model was described for Syringoporicae corals (Tabulata) and it is similar to the coordinated-growth mode described in scleractinians and molluscs. Calceola skeletons show also a convergent structure with scleractinian forming Rapid Accretion Deposits (RAD), which share some structural and chemical properties. These evidences suggest analogous processes of biomineralization derived from a stem group of cnidarians. The results of this paper highlight the value of biomineralization studies in fossil organisms to understand the evolution of biomineralization mechanism through Phanerozoic.
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Affiliation(s)
- Ismael Coronado
- Departamento de Paleontología, Universidad Complutense de Madrid, C/ José Antonio Nováis 2, Ciudad Universitaria, E-28040 Madrid, Spain.
| | - Alberto Pérez-Huerta
- Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA.
| | - Sergio Rodríguez
- Departamento de Paleontología, Universidad Complutense de Madrid, C/ José Antonio Nováis 2, Ciudad Universitaria, E-28040 Madrid, Spain; Instituto de Geociencias (IGEO. CSIC-UCM), C/ José Antonio Nováis 2, Ciudad Universitaria, E-28040 Madrid, Spain.
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Stolarski J, Bosellini FR, Wallace CC, Gothmann AM, Mazur M, Domart-Coulon I, Gutner-Hoch E, Neuser RD, Levy O, Shemesh A, Meibom A. A unique coral biomineralization pattern has resisted 40 million years of major ocean chemistry change. Sci Rep 2016; 6:27579. [PMID: 27302371 PMCID: PMC4908604 DOI: 10.1038/srep27579] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/17/2016] [Indexed: 12/17/2022] Open
Abstract
Today coral reefs are threatened by changes to seawater conditions associated with rapid anthropogenic global climate change. Yet, since the Cenozoic, these organisms have experienced major fluctuations in atmospheric CO2 levels (from greenhouse conditions of high pCO2 in the Eocene to low pCO2 ice-house conditions in the Oligocene-Miocene) and a dramatically changing ocean Mg/Ca ratio. Here we show that the most diverse, widespread, and abundant reef-building coral genus Acropora (20 morphological groups and 150 living species) has not only survived these environmental changes, but has maintained its distinct skeletal biomineralization pattern for at least 40 My: Well-preserved fossil Acropora skeletons from the Eocene, Oligocene, and Miocene show ultra-structures indistinguishable from those of extant representatives of the genus and their aragonitic skeleton Mg/Ca ratios trace the inferred ocean Mg/Ca ratio precisely since the Eocene. Therefore, among marine biogenic carbonate fossils, well-preserved acroporid skeletons represent material with very high potential for reconstruction of ancient ocean chemistry.
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Affiliation(s)
- Jarosław Stolarski
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland
| | - Francesca R Bosellini
- Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, Via Campi 103, 41125 Modena, Italy
| | - Carden C Wallace
- Biodiversity &Geosciences Program, Queensland Museum, South Brisbane, Qld 4101, Australia
| | - Anne M Gothmann
- University of Washington, School of Oceanography, Box 357940, WA 98195-7940, Seattle, USA
| | - Maciej Mazur
- Department of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Isabelle Domart-Coulon
- MCAM UMR7245 Muséum National d'Histoire Naturelle - CNRS, Sorbonne-Universités, Paris, France
| | - Eldad Gutner-Hoch
- The Mina &Everard Goodman Faculty of Life Science, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - Rolf D Neuser
- Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, D-44780 Bochum, Germany
| | - Oren Levy
- The Mina &Everard Goodman Faculty of Life Science, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - Aldo Shemesh
- Department of Earth and Planetary Sciences, The Weizmann Institute of Science, P.O. Box 26, 76100 Rehovot, Israel
| | - Anders Meibom
- 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, Université de Lausanne, CH-1015 Lausanne, Switzerland
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8
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Thil F, Blamart D, Assailly C, Lazareth CE, Leblanc T, Butsher J, Douville E. Development of laser ablation multi-collector inductively coupled plasma mass spectrometry for boron isotopic measurement in marine biocarbonates: new improvements and application to a modern Porites coral. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:359-371. [PMID: 26754128 DOI: 10.1002/rcm.7448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 10/19/2015] [Accepted: 11/02/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Laser Ablation coupled to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICPMS) is a powerful tool for the high-precision measurement of the isotopic ratios of many elements in geological samples, with the isotope ratio ((11) B/(10) B) of boron being used as an indicator of the pH of oceanic waters. Most geological samples or standards are polished and ablation occurs on flat surfaces. However, the shape and the irregularities of marine biocarbonates (e.g., corals, foraminifera) can make precise isotopic measurements of boron difficult. Even after polishing, the porosity properties and the presence of holes or micro-fractures affect the signal and the isotopic ratio when ablating the material, especially in raster mode. METHODS The effect of porosity and of the crater itself on the (11) B signal and the isotopic ratio acquired by LA-MC-ICPMS in both raster and spot mode was studied. Characterization of the craters was then performed with an optical profilometer to determine their shapes and depths. Surface state effects were examined by analyzing the isotopic fractionation of boron in silicate (NIST-SRM 612 and 610 standards) and in carbonate (corals). RESULTS Surface irregularities led to a considerable loss of signal when the crater depth exceeded 20 µm. The stability and precision were degraded when ablation occurred in a deep cavity. The effect of laser focusing and of blank correction was also highlighted and our observations indicate that the accuracy of the boron isotopic ratio does not depend on the shape of the surface. After validation of the analytical protocol for boron isotopes, a raster application on a Porites coral, which grew for 18 months in an aquarium after field sampling, was carried out. CONCLUSIONS This original LA-MC-ICPMS study revealed a well-marked boron isotope ratio temporal variability, probably related to growth rate and density changes, irrespective of the pH of the surrounding seawater. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- François Thil
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL, UMR 8212 CNRS CEA-UVSQ), 91198, Gif-sur-Yvette Cedex, France
| | - Dominique Blamart
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL, UMR 8212 CNRS CEA-UVSQ), 91198, Gif-sur-Yvette Cedex, France
| | - Caroline Assailly
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL, UMR 8212 CNRS CEA-UVSQ), 91198, Gif-sur-Yvette Cedex, France
- IRD-Sorbonne Universités (UPMC, Univ. Paris 06)-CNRS-MNHN, LOCEAN Laboratory, IRD France-Nord, 32, avenue Henri Varagnat, F-93143, Bondy, France
| | - Claire E Lazareth
- IRD-Sorbonne Universités (UPMC, Univ. Paris 06)-CNRS-MNHN, LOCEAN Laboratory, IRD France-Nord, 32, avenue Henri Varagnat, F-93143, Bondy, France
| | - Thierry Leblanc
- Group of Electrical Engineering, Paris (CNRS, Centrale Supelec, Paris-Sud, UPMC), 11 rue Joliot Curie, Plateau de Moulon, 91192, Gif sur Yvette Cedex, France
| | - John Butsher
- IRD-Sorbonne Universités (UPMC, Univ. Paris 06)-CNRS-MNHN, LOCEAN Laboratory, IRD France-Nord, 32, avenue Henri Varagnat, F-93143, Bondy, France
| | - Eric Douville
- Laboratoire des Sciences du Climat et de l'Environnement (LSCE/IPSL, UMR 8212 CNRS CEA-UVSQ), 91198, Gif-sur-Yvette Cedex, France
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Gutner-Hoch E, Schneider K, Stolarski J, Domart-Coulon I, Yam R, Meibom A, Shemesh A, Levy O. Evidence for Rhythmicity Pacemaker in the Calcification Process of Scleractinian Coral. Sci Rep 2016; 6:20191. [PMID: 26847144 PMCID: PMC4742845 DOI: 10.1038/srep20191] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 12/17/2015] [Indexed: 11/09/2022] Open
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.
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Affiliation(s)
- Eldad Gutner-Hoch
- The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - Kenneth Schneider
- The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
| | - Jaroslaw Stolarski
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland
| | - Isabelle Domart-Coulon
- MCAM UMR7245, Sorbonne Universités, Muséum National d'Histoire Naturelle, (CP54) 57 rue Cuvier, 75005 Paris, France
| | - Ruth Yam
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, P.O.Box 26, 76100 Rehovot, Israel
| | - Anders Meibom
- 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
| | - Aldo Shemesh
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, P.O.Box 26, 76100 Rehovot, Israel
| | - Oren Levy
- The Mina &Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 52900 Ramat-Gan, Israel
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10
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Frankowiak K, Kret S, Mazur M, Meibom A, Kitahara MV, Stolarski J. Fine-Scale Skeletal Banding Can Distinguish Symbiotic from Asymbiotic Species among Modern and Fossil Scleractinian Corals. PLoS One 2016; 11:e0147066. [PMID: 26751803 PMCID: PMC4713449 DOI: 10.1371/journal.pone.0147066] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/27/2015] [Indexed: 12/27/2022] Open
Abstract
Understanding the evolution of scleractinian corals on geological timescales is key to predict how modern reef ecosystems will react to changing environmental conditions in the future. Important to such efforts has been the development of several skeleton-based criteria to distinguish between the two major ecological groups of scleractinians: zooxanthellates, which live in symbiosis with dinoflagellate algae, and azooxanthellates, which lack endosymbiotic dinoflagellates. Existing criteria are based on overall skeletal morphology and bio/geo-chemical indicators-none of them being particularly robust. Here we explore another skeletal feature, namely fine-scale growth banding, which differs between these two groups of corals. Using various ultra-structural imaging techniques (e.g., TEM, SEM, and NanoSIMS) we have characterized skeletal growth increments, composed of doublets of optically light and dark bands, in a broad selection of extant symbiotic and asymbiotic corals. Skeletons of zooxanthellate corals are characterized by regular growth banding, whereas in skeletons of azooxanthellate corals the growth banding is irregular. Importantly, the regularity of growth bands can be easily quantified with a coefficient of variation obtained by measuring bandwidths on SEM images of polished and etched skeletal surfaces of septa and/or walls. We find that this coefficient of variation (lower values indicate higher regularity) ranges from ~40 to ~90% in azooxanthellate corals and from ~5 to ~15% in symbiotic species. With more than 90% (28 out of 31) of the studied corals conforming to this microstructural criterion, it represents an easy and robust method to discriminate between zooxanthellate and azooxanthellate corals. This microstructural criterion has been applied to the exceptionally preserved skeleton of the Triassic (Norian, ca. 215 Ma) scleractinian Volzeia sp., which contains the first example of regular, fine-scale banding of thickening deposits in a fossil coral of this age. The regularity of its growth banding strongly suggests that the coral was symbiotic with zooxanthellates.
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Affiliation(s)
- Katarzyna Frankowiak
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland
| | - Sławomir Kret
- Institute of Physics, Polish Academy of Sciences, Lotników 32/46, PL-02-668 Warsaw, Poland
| | - Maciej Mazur
- Department of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw, Poland
| | - Anders Meibom
- Laboratory for Biological Geochemistry, School of Architecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Center for Advanced Surface Analysis, Institute of Earth Sciences, Université de Lausanne, CH-1015 Lausanne, Switzerland
| | - Marcelo V. Kitahara
- Departamento de Cięncias do Mar, Universidade Federal de SăoPaulo, Campus Baixada Santista, 11030–400 Santos, Brasil
| | - Jarosław Stolarski
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, PL-00-818 Warsaw, Poland
- * E-mail:
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Falini G, Fermani S, Goffredo S. Coral biomineralization: A focus on intra-skeletal organic matrix and calcification. Semin Cell Dev Biol 2015; 46:17-26. [DOI: 10.1016/j.semcdb.2015.09.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/30/2015] [Accepted: 09/02/2015] [Indexed: 11/30/2022]
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Immunolocalization of skeletal matrix proteins in tissue and mineral of the coral Stylophora pistillata. Proc Natl Acad Sci U S A 2014; 111:12728-33. [PMID: 25139990 DOI: 10.1073/pnas.1408621111] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The precipitation and assembly of calcium carbonate skeletons by stony corals is a precisely controlled process regulated by the secretion of an ECM. Recently, it has been reported that the proteome of the skeletal organic matrix (SOM) contains a group of coral acid-rich proteins as well as an assemblage of adhesion and structural proteins, which together, create a framework for the precipitation of aragonite. To date, we are aware of no report that has investigated the localization of individual SOM proteins in the skeleton. In particular, no data are available on the ultrastructural mapping of these proteins in the calcification site or the skeleton. This information is crucial to assessing the role of these proteins in biomineralization. Immunological techniques represent a valuable approach to localize a single component within a calcified skeleton. By using immunogold labeling and immunohistochemical assays, here we show the spatial arrangement of key matrix proteins in tissue and skeleton of the common zooxanthellate coral, Stylophora pistillata. To our knowledge, our results reveal for the first time that, at the nanoscale, skeletal proteins are embedded within the aragonite crystals in a highly ordered arrangement consistent with a diel calcification pattern. In the tissue, these proteins are not restricted to the calcifying epithelium, suggesting that they also play other roles in the coral's metabolic pathways.
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Ultrascale and microscale growth dynamics of the cidaroid spine ofPhyllacanthus imperialisrevealed by26Mg labeling and NanoSIMS isotopic imaging. J Morphol 2014; 275:788-96. [DOI: 10.1002/jmor.20260] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/21/2014] [Accepted: 02/02/2014] [Indexed: 11/07/2022]
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