Cerastoderma edule

The common or edible cockle ( Cerastoderma edule )

The Cockle, or even edible cockle ( Cerastoderma edule ) is a species of bivalve mollusc of the order Veneroida. The Cockle Shell in the North Sea is the most commonly found.

Features

The enclosure of the commons cockle is usually oblong- elliptical, and about five inches long. The shape is variable. The housing is relatively strong and thick- arched. The surface is ornamented with 20 to 28 mm wide, rounded ribs which are crossed by concentric finer growth lines. At the crossing points fine scales are formed. The color varies from white to yellow -brown to brown. The lock has the right valve two cardinal teeth and two front and two rear side teeth. In the left valve there are two cardinal teeth and one front and rear side tooth. The ligament is on the outside. The front and rear sphincter are approximately equal ( isomyar ). The siphons are relatively short. The surface line is ganzrandig ( integripalliat ).

Lifestyle and deposits

The Cockle preferred sandy- silty soils 0 to about 10 m depth. In the tidal influenced areas (Watt ) of the North Sea is the most common shellfish species; approximately 3 m water depth, the greatest population density is achieved with up to 245 individuals per square meter arising. She lives buried just below the sediment surface not deeper than 5 cm, their short siphons rich just at the sediment surface. If they flushed, they may again relatively quickly dig with her foot (about 2-10 minutes). Often it moves on the surface a bit further before they dig again. It bears relatively low oxygen concentrations and may even survive for several days in an oxygen-free environment. It is relatively tolerant of fluctuations in salinity, but requires about 10 ‰ salt. Eggs and sperm are released in late May into the open waters, where it comes to fertilization. A female produces 5000-50000 eggs per breeding season. The larvae are still alive about 2 to 3 weeks in the open water before they move on to the soil life. The animals are usually about 3 years old, under particularly favorable conditions up to 9 years.

Dissemination

The species is found to Mauritania to the south in the eastern North Atlantic from the Barents Sea in the north. It is one of the most common clams in the North Sea and also occurs in the western Baltic Sea. However, it seems to be missing in the Mediterranean.

Commercial importance

As the name implies edible cockle, mussel is caught commercially. In the Netherlands alone about 2,500 million units in 1993 fished.

Similar Species

The Cockle is very similar to the related species Cerastoderma lamarcki in the shape of the housing.