Deciphering the distribution of organic components in brachiopod shells by confocal laser scanning microscopy

Characterization of the nature and distribution of organic components is crucial to understand shell formation in marine invertebrates. Although several techniques can provide detailed information at high spatial resolution, few of them are non-destructive and informative in a larger structural context. We explore the use of confocal laser scanning microscopy (CLSM) to obtain a better understanding of the distribution of organic components in calcitic shells of brachiopods focusing on perforations (punctae) across the shell. Resulting intensities and patterns of fluorescence correspond well with the distribution of polysaccharides and proteins as reported in previous histological and biochemical studies. Confocal laser microscopy is, therefore, a useful tool to be combined with other techniques to improve our knowledge of biomineral structures in marine invertebrates.