This flattened, irregularly shaped shell is a European Flat Oyster (Ostrea edulis), native to the coastal waters of Europe, including the UK. The shell is rough and asymmetrical, often grey to yellowish in colour, with a smoother, cupped lower valve and flatter upper valve. A prized delicacy for centuries, Ostrea edulis forms dense beds in shallow estuaries and tidal flats, where it plays a crucial ecological role as a filter feeder.

Location:
Northeast Atlantic, including the UK and Irish coasts, inhabiting estuaries and shallow coastal waters.

Average Size:
5–11 cm in diameter.

Family:
Ostreidae (True Oysters)

Species:
Ostrea edulis

Ecological Role:
A keystone species, the European Flat Oyster helps improve water quality by filtering plankton and organic matter. Its beds provide essential habitat and food for marine species such as crabs, fish, and invertebrates.

Reproduction:
European Flat Oysters are hermaphroditic, with individuals capable of alternating between male and female roles. Fertilisation is internal, and larvae are brooded before being released into the water column.

Conservation Status:
Populations have declined due to overfishing, habitat loss, pollution, and disease. Conservation measures include habitat restoration, sustainable harvesting, and restocking from hatcheries to support ecosystem recovery.

Collection Date:
This specimen was collected in Exmouth on 03/09/1901.