''Ostrea edulis'', commonly known as the European flat oyster, is a species of
oyster
Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...
native to
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
. In Britain and Ireland, regional names include Colchester native oyster, mud oyster, or edible oyster. In France, ''Ostrea edulis'' are known as ''huîtres plates'' (flat oysters) except for those that come from the Belon River estuary in
Brittany
Brittany (; french: link=no, Bretagne ; br, Breizh, or ; Gallo language, Gallo: ''Bertaèyn'' ) is a peninsula, Historical region, historical country and cultural area in the west of modern France, covering the western part of what was known ...
, France, which are known as Belons.
The fossil record of this species dates back to the
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
(age range: 15.97 million years ago to present day). Fossils have been found in Belgium, Italy, the Netherlands, Egypt, Greece, Spain, the United Kingdom, Austria, France and Germany.
Description
When mature, ''O. edulis'' adults range from across.
Shells are oval or pear shaped, white, yellowish or cream in colour, with a rough surface showing pale brown or bluish concentric bands on the right valve. The two valves are quite different in shape and size, as the left one is concave and fixed to the substratum, while the right one is almost flat and fits inside the left. The inner surface is smooth, whitish or bluish-grey.
Biology
''Ostrea edulis'' are gregarious molluscs that start their lives as males. They mature sexually after eight–ten months and may change sex depending on the water temperature. Usually the lifespan can reach about six years, with a maximum of 15 years. Adult oysters feed by filtration.
Distribution
The species naturally ranges along the western and southern coasts of
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
from
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
to
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
and including most of the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
and the
Mediterranean
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...
coast.
Naturally viable populations have appeared in eastern
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
from
Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...
to
Rhode Island
Rhode Island (, like ''road'') is a U.S. state, state in the New England region of the Northeastern United States. It is the List of U.S. states by area, smallest U.S. state by area and the List of states and territories of the United States ...
subsequent to artificial introduction in the 1940s and 1950s.
Habitat
''Ostrea edulis'' can be found in estuarine and shallow coastal water with hard substrata of mud and rocks.
Human use
''Ostrea edulis'' has been harvested throughout Europe as an important food source since prehistory. During Roman occupation of Britain ''O. edulis'' oysters were exported in large quantities back to Italy. However, due to their robust nature and ease of cultivation the
Pacific oyster
The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas''), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand.
Etymology
The genus ''Mag ...
s, ''
Crassostrea gigas
The Pacific oyster, Japanese oyster, or Miyagi oyster (''Magallana gigas''), is an oyster native to the Pacific coast of Asia. It has become an introduced species in North America, Australia, Europe, and New Zealand.
Etymology
The genus ''Maga ...
'', account for more than 75 percent of Europe's oyster production.
European flat oysters are famously grown in Brittany, France. The true Belon oyster is cultivated in the Belon River, France, and has the
AOC
Alexandria Ocasio-Cortez (; ; born October 13, 1989), also known by her initials AOC, is an American politician and activist. She has served as the U.S. representative for New York's 14th congressional district since 2019, as a member of ...
protected name. In the 1950s, Dutch scientists artificially introduced Belon oyster seed into the waters around
Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...
in hopes to establish a viable stock. The initial project was abandoned but ten years later natural colonies of flat oysters were found in the wild.
Many North American suppliers use the name 'Belon' to species that are found in the wild throughout the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
.
![European Flat Oyster](https://upload.wikimedia.org/wikipedia/commons/f/f7/European_Flat_Oyster.jpg)
''Ostrea edulis'' is now also being
mariculture
Mariculture or marine farming is a specialized branch of aquaculture (which includes freshwater aquaculture) involving the cultivation of marine organisms for food and other animal products, in enclosed sections of the open ocean ( offshore mari ...
d in the states of
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
,
Maine
Maine () is a state in the New England and Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Canadian provinces of New Brunswick and Quebec to the northeast and north ...
, and
Washington
Washington commonly refers to:
* Washington (state), United States
* Washington, D.C., the capital of the United States
** A metonym for the federal government of the United States
** Washington metropolitan area, the metropolitan area centered on ...
in the United States. The species once dominated European oyster production but disease, pollution, and overfishing sharply reduced the harvest.
Currently, there are efforts across Germany, the UK, France, Scotland, and Wales to
restore oyster reefs and maintain the habitat.
U.S.
oyster growers farm ''O. edulis'' in small quantities on both coasts. They are prized for their unique tannic seawater flavour, sometimes described as dry and metallic, and are more expensive than other American oysters.
The flavour is considered excellent for eating raw on the half shell.
The adductor muscle of the European flat in combination with the shape of the shell results in a somewhat weaker seal compared with other oyster species. It is common practice to use rubber bands to prevent oysters from spilling their liquor and dehydrating in storage before consumption.
See also
*
References
External links
UK Biodiversity Action Plan
{{Taxonbar, from=Q729678
Ostrea
Commercial molluscs
Molluscs described in 1758
Taxa named by Carl Linnaeus