The common cockle (''Cerastoderma edule'') is a
species of edible saltwater
clam, a
marine
Marine is an adjective meaning of or pertaining to the sea or ocean.
Marine or marines may refer to:
Ocean
* Maritime (disambiguation)
* Marine art
* Marine biology
* Marine debris
* Marine habitats
* Marine life
* Marine pollution
Military
* ...
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
in the family
Cardiidae, the cockles. It is found in waters off Europe, from Iceland in the north, south into waters off western Africa as far south as Senegal. The ribbed oval shells can reach across and are white, yellowish or brown in colour. The common cockle is harvested commercially and eaten in much of its range.
Taxonomy and naming

The common cockle was one of the many
invertebrate species originally described by
Carl Linnaeus in the landmark 1758
10th edition
1 (one, unit, unity) is a number representing a single or the only entity. 1 is also a numerical digit and represents a single unit of counting or measurement. For example, a line segment of ''unit length'' is a line segment of length 1. I ...
of ''
Systema Naturae
' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...
'', where it was given its old binomial name ''Cardium edule''. The species name is derived from the
Latin adjective ''ĕdūlis'' "edible". Italian naturalist
Giuseppe Saverio Poli erected the genus ''
Cerastoderma'' in 1795, making the common cockle the type species as ''Cerastoderma edule''.
[ The genus name is derived from the Ancient Greek words ''keras'' "horn" and ''derma'' "skin".][ For many years it was referred to by both names.][
Other common names in English are edible cockle and common edible cockle.][ On account of its heart-like shape, it is called the "heart mussel" in German and Scandinavian languages (''Hertzmuschel'' and ''Hjertemusling'', respectively).][Davidson, Alan. ]
The Oxford Companion to Food
', p. 201 ( Oxford University Press, 2014).
Description
It typically reaches from to in length,[Considine, Douglas and Considine, Glenn. ]
Van Nostrand's Scientific Encyclopedia
', p. 2086 (Springer Science & Business Media, 2013). but sometimes it reaches . The shells are pale or whitish yellow, grubby white, or brown. The shell is oval, and covered by ribs, which are flattened in the middle part of the shell. The digestive glands are light brown to dark green.
In contrast, the similar lagoon cockle
''Cerastoderma glaucum'', the lagoon cockle, is a species of saltwater clam, a marine bivalve mollusc in the family Cardiidae, the cockles.
This species is found along the coasts of Europe and North Africa, including the Mediterranean and Black ...
has an elongated shell posteriorly, black digestive glands and is found in substrate of stagnant water.[
]
Distribution and habitat
This species is found in coastal areas of the northern and eastern Atlantic Ocean. It is widely distributed from Iceland and Norway in Europe, to Senegal along the coast of west Africa. The common cockle is one of the most abundant species of molluscs in tidal flats located in the bays and estuaries of Europe. It plays a major role as a source of food for crustaceans, fish, and wading birds.
''Cerastoderma edule edule''
Right and left valve of the same specimen:
File:Cerastoderma edule 01.jpg, Right valve
File:Cerastoderma edule 02.jpg, Left valve
''Cerastoderma edule belgicum''
Right and left valve of the same specimen:
File:Cerastoderma edule belgicum 01.jpg, Right valve
File:Cerastoderma edule belgicum 02.jpg, Left valve
''Cerastoderma edule maculatum''
Right and left valve:
File:Cerastoderma edule maculatum 01.jpg, Right valve
File:Cerastoderma edule maculatum 02.jpg, Left valve
Ecology
This species is a filter feeder
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feedin ...
, meaning that it feeds by straining water to obtain suspended matter and food particles.[Dauvin, Jean-Claude. ]
Biological heritage and food chains
', p. 25 (Quae, , 2006). Water is inhaled through an inhalant siphon, and exhaled through an exhalant siphon.
It tolerates a wide range of salinity (euryhaline
Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (''Poecilia sphenops'') which can live in fresh water, brackish water, or salt water.
The green crab (''Carcinus maenas'') is an e ...
), and wide range of temperatures (eurythermic
A eurytherm is an organism, often an endotherm, that can function at a wide range of ambient temperatures. To be considered a eurytherm, all stages of an organism's life cycle must be considered, including juvenile and larval stages. These wi ...
), which helps to explain its very extensive range. It has a first spawning period in early summer, and a second one in the fall. Lifespan is typically five to six years, though it may perish earlier due to predation by humans as well as crab
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...
s, flounder
Flounders are a group of flatfish species. They are demersal fish, found at the bottom of oceans around the world; some species will also enter estuaries.
Taxonomy
The name "flounder" is used for several only distantly related species, thou ...
, and various birds especially including oystercatchers. A green shore crab ('' Carcinus maenas'') can consume up to 40 common cockles a day, eating smaller cockles (under 1.5 cm diameter) much more quickly than larger ones. Hence they could have a greater impact in lean seasons where cockles did not grow so quickly.
Parasites and diseases
The cercozoa
Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eu ...
n species '' Marteilia cochillia'' is a parasite of the common cockle, having caused a collapse in commercial harvests of cockle beds in Galicia
Galicia may refer to:
Geographic regions
* Galicia (Spain), a region and autonomous community of northwestern Spain
** Gallaecia, a Roman province
** The post-Roman Kingdom of the Suebi, also called the Kingdom of Gallaecia
** The medieval King ...
in 2012.
A survey of cockle beds in Galicia found that infestation by the gregarine parasite ''Nematopsis
''Nematopsis'' (Nee-mah-top-cis) is a genus gregarine Apicomplexan of the family Porosporidae. It is an aquatic parasite of crustaceans with a molluscan intermediate host. Nematopsis has been distinguished from the similar genus ''Porospora'' by ...
'' was widespread, and that the most common pathological finding was disseminated neoplasia.
Uses
These animals were probably a significant food source in hunter-gatherer societies of prehistoric Europe, and the clay remains of shell-imprints have been found. The clay is imprinted with fine decorations, repetitions of the distinct curved ridges, undulating lines and/or edges characteristic to the cockle shell, a natural resource of coastal waters.
Cardial ware is the name of the Neolithic pottery from maritime cultures that colonized Mediterranean shores c. 6000 – 5,500 BC, this name being based upon the old binomial name of the species: ''Cardium edule''.
In the 1800s, a song called " Molly Malone" was first published (also known as "Cockles and Mussels"), later becoming the unofficial song of Dublin, Ireland. The lyrics describe Molly Malone selling the common cockle in the streets of that city.
As food
This cockle is cooked and eaten in several countries (including the United Kingdom, France, Germany, Ireland, Japan, Portugal and Spain). It is also sometimes eaten pickled, or raw.
An important species for the fishing industry, it is commercially fished in the United Kingdom, Ireland and France by suction dredge and also raking by hand. Previously the greatest catch was from the Netherlands, but now fisheries restrictions have been put in place due to environmental concerns. Similar measures have been established elsewhere, for example in Scotland where dredging with vehicles is prohibited, and in parts of England and Wales where only old-fashioned hand-gathering is permitted (using a long plank that is rocked back and forth on the sand).
This species is also used in aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lot ...
. Farming of cockles is ongoing in the UK, the Netherlands and Portugal. However, production in those countries has not been very stable; for example, production fell from 107,800 tons in 1987 to 40,900 tons in 1997.[Spencer, Brian. ]
Molluscan Shellfish Farming
', p. 103 (John Wiley & Sons, 2008). In addition to being a food source, their shells have also been used industrially as a source of lime.
Gathering this species can be dangerous. In 2004, the incoming tide at Morecambe Bay in England caused 23 cockle-gatherers to die.[Chambers, Paul. ]
British Seashells: A Guide for Collectors and Beachcombers
', p. 158 ( Casemate Publishers, 2009).
References
External links
*
{{Taxonbar , from=Q21124
Cardiidae
Commercial molluscs
Molluscs described in 1758
Taxa named by Carl Linnaeus
Molluscs of the Atlantic Ocean
Molluscs of the Mediterranean Sea
Molluscs of the Black Sea
Marine molluscs of Europe
Bivalves of Europe
Marine molluscs of Africa