The Zeeland flat oyster is a concept, but nowadays it is no longer common in the waters of Zeeland. In order to meet the high demand of flat oysters, adult flat oysters are imported on a large scale and placed in the waters of Zeeland. After a few months of stay, the oyster gets the specific taste and eventually gets the predicate of Zeeland oyster. Oysters can be grown by turning out oyster seeds on collectors, and then the small oyster that is found on plots. If the oyster is large enough, it is traded or exported. The flat oyster has a flat round shell, and is sexually mature after 8 months. Most flat oysters originate from Denmark or Ireland.