1Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
2GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Wischhofstraße 1–3, 24148 Kiel, Germany
Received: 25 Jun 2012 – Discussion started: 10 Jul 2012
Abstract. Confocal Raman microscopy (CRM) mapping was used to investigate the microstructural arrangement and organic matrix distribution within the skeleton of the coral Porites lutea. Relative changes in the crystallographic orientation of crystals within the fibrous fan-system could be mapped, without the need to prepare thin sections, as required if this information is obtained by polarized light microscopy. Simultaneously, incremental growth lines can be visualized without the necessity of etching and hence alteration of sample surface. Using these methods two types of growth lines could be identified: one corresponds to the well-known incremental growth layers, whereas the second type of growth lines resemble denticle finger-like structures (most likely traces of former spines or skeletal surfaces). We hypothesize that these lines represent the outer skeletal surface before another growth cycle of elongation, infilling and thickening of skeletal areas continues. We show that CRM mapping with high spatial resolution can significantly improve our understanding of the micro-structural arrangement and growth patterns in coral skeletons.
Revised: 02 Nov 2012 – Accepted: 09 Nov 2012 – Published: 28 Nov 2012
Wall, M. and Nehrke, G.: Reconstructing skeletal fiber arrangement and growth mode in the coral Porites lutea (Cnidaria, Scleractinia): a confocal Raman microscopy study, Biogeosciences, 9, 4885-4895, doi:10.5194/bg-9-4885-2012, 2012.