Formation de chambres dans la coquille de l'huitre plate Ostrea edulis L. cultivee dans les rias de Galice.

The formation of anomalies in the calcification of the shell in the flat oyster Ostrea edulis , is not a recent phenomenon. The authors used spat of oyster from France and Greece cultured in the Arosa Estuary, Galicia, Spain, through the punt or floating park system very spread in the Galician estuary. The calculation of different indices of condition show us that the formation of blisters increases the grade of the shell concavity and it does not affect the meat content of the oyster. The studies of crystallization in the calcareous layers that form the blisters, prove the "calcite", as the only type of crystal and the existence of disorder and disorientiation in the growing of the crystals.