Microstructure and crystallography of the wall plates of the giant barnacle Austromegabalanus psittacus: a material organized by crystal growth

摘要: In biomineralization, it is essential to know the microstructural and crystallographic organization of natural hard tissues. This knowledge virtually absent in case barnacles. Here, we have examined crystal morphology orientation wall plates giant barnacle Austromegabalanus psittacus by means optical electron microscopy, backscatter diffraction. The are made calcite grains, which change from irregular rhombohedral, except for radii alae, where fibrous produced. Both grains fibres arrange into bundles crystallographically co-oriented units, grow onto each other epitaxially. We call these areas coherent regions (CCRs). Each CCR elongates disposes its c-axis perpendicularly or at a high angle growth surfaces, whereas a-axes adjacent CCRs differ orientation. absence obvious organic matrices, this pattern interpreted be produced purely processes. particular, due competition, orient their fastest axes perpendicular surface. Since an aggregate axis that along crystals stack up more rapidly, is, granular calcite. summary, material forming studied barnacles under very little biological control main role mantle cells provide construction materials front.