The aim of his NEWFELPRO project was to explore and describe the fabrication of the shell during the larval development, in selected marine and terrestrial mollusks. To this aim, two approaches are used: ultrastructural and molecular. For the first, larval shells is analyzed according to sophisticated analytical techniques including Infra-Red and Raman spectroscopy, X-ray diffraction, scanning and transmission electron microscopy. The molecular aspects are tackled, by using proteomics and immunohistological techniques, in order to identify the protein assemblage required for early shell mineralization. Particular attention is paid to enzymatic markers. Besides a deepened understanding of the larval shell formation process, this project provides a platform for using molecular markers to study the impact of environmental changes (e.g. Ocean Acidification) on shell biomineralization.