Fig. 6

Schematic representation of the different stages of eggshell deposition. Mineralization starts by massive accumulation of ACC at 5 h post-ovulation. ACC is transformed into ACC aggregates (6 h p.o.), and larger crystal units then form with their c-axes progressively perpendicular to the surface (7–10 h p.o.). During the growth phase (10–22 h p.o.), the compact layer (palisade layer) is deposited with all crystals oriented perpendicular to the surface. Two hours before oviposition, arrest of mineralization occurs and the thin organic cuticle layer is deposited. Arrows indicate the orientation of the c-axis of calcite crystals