The Romans imported oysters from England to Italy by boat – and Roman Emperors reportedly paid for them by their weight ... open an oyster to seize its pearl. But the expression’s meaning ...

In reality, most pearls develop around parasitic organisms. The oyster’s response to these intruders is to encase them in nacre, leading to pearl formation. Natural pearls vary in size ...

Even isolating apparently healthy oysters has had no effect: the disease seems to ferret them out. Pearl farmers haul out their oyster cages in Ago Bay. Government and company researchers both ...