CHARACTERISTICS OF CALCIFICATION PROCESSES IN EMBRYOS AND LARVAE OF THE PACIFIC OYSTER, CRASSOSTREA GIGAS

摘要

The mineralization sequence with respect to development stages of Crassostrea gigas (Thunberg, 1793), namely from the embryonic and larval stages to the juvenile stage oyster, was analyzed by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). At each stage, the oyster shell underwent a polymorphic change, and there were significant alterations in organic component and protein conformation. A linear increase in HCO_3~- with development was reflective of carbonic anhydrase activity. The β-sheet was the main larval component in the prodissoconch Ⅱ stage related to the formation of aragonite. The composition of the organic matrix and the polymorphism of biominerals for the shell formation were almost completed by the dissoconch stage.