Reconstructing skeletal fiber arrangement and growth mode in the coral iPorites lutea/i (Cnidaria, Scleractinia): a confocal Raman microscopy study

摘要

Confocal Raman microscopy (CRM) mapping was used to investigate themicrostructural arrangement and organic matrix distribution within theskeleton of the coral Porites lutea. Relative changes in the crystallographic orientationof crystals within the fibrous fan-system could be mapped, without the needto prepare thin sections, as required if this information is obtained bypolarized light microscopy. Simultaneously, incremental growth lines can bevisualized without the necessity of etching and hence alteration of samplesurface. Using these methods two types of growth lines could be identified:one corresponds to the well-known incremental growth layers, whereas thesecond type of growth lines resemble denticle finger-like structures (mostlikely traces of former spines or skeletal surfaces). We hypothesize thatthese lines represent the outer skeletal surface before another growth cycleof elongation, infilling and thickening of skeletal areas continues. We showthat CRM mapping with high spatial resolution can significantly improve ourunderstanding of the micro-structural arrangement and growth patterns incoral skeletons.