Cerastoderma glaucum

Researched By	Nicola White	Data Supplied By	MarLIN
Refereed by	Dr Richard S.K. Barnes
Taxonomy
Scientific name	Cerastoderma glaucum	Common name	Lagoon cockle
MCS Code	W1962	Recent Synonyms	Cardium lamarckii
Phylum	Mollusca	Subphylum
Superclass		Class	Pelecypoda
Subclass		Order	Veneroida
Suborder		Family	Cardiidae
Genus	Cerastoderma	Species	glaucum
Subspecies
Additional Information	No text entered
Taxonomy References	Howson & Picton, 1997
General Biology
Growth form	Bivalved	Feeding method	Active suspension feeder
Mobility/Movement	Burrower	Environmental position	Infaunal
Typical food types	No text entered	Habit	Free living
Bioturbator		Flexibility	None (< 10 degrees)
Fragility	Robust	Size	Small-medium(3-10cm)
Height	Insufficient information	Growth Rate	9.6 mm/year
Adult dispersal potential	100-1000m	Dependency	Independent
Sociability	Solitary
Toxic/Poisonous?	No
Additional Information	The species exists in two forms, a typical thin-shelled variety found in brackish lagoon habitats and a thicker shelled variety occurring in estuaries. Growth rate during the first year takes place at a mean of 9.6 mm per year in Essex. Thereafter growth rate decreases to 4.9 mm in the second year and 2.5 mm in the third year (Boyden, 1972).
Biology References	Barnes, 1973, Boyden, 1972, Boyden & Russel, 1972, Barnes, 1980b, Barnes, 1994, Brock, 1979, Rygg, 1970, Ansell et al., 1981
Distribution and Habitat
Distribution in Britain & Ireland	Orkney, Firth of Forth, East Anglia, Deben & Orwell estuaries, south coast of England, south Wales, the west coast of Scotland, and south and west coasts of Ireland.
Global distribution	Occurs from Norway and the Baltic to the Mediterranean and Black Seas.
Biogeographic range	Not researched	Depth range	Shallow
Migratory	Non-migratory / Resident
Distribution Additional Information	The adult and juvenile populations are distributed differently. Juveniles (0.5-10 mm) attach to filamentous algae by means of byssus threads. When they reach a certain age, they migrate to the adult free-living sediment population (Labourg & Lasserre, 1980).
Substratum preferences	Coarse clean sand, Fine clean sand, Sandy mud, Muddy sand, Mud	Physiographic preferences	Estuary, Isolated saline water (Lagoon)
Biological zone	Lower Eulittoral, Sublittoral Fringe	Wave exposure	Sheltered, Very Sheltered
Tidal stream strength/Water flow	Weak (<1 kn)	Salinity	Low (<18 psu), Variable (18-40 psu)
Habitat Additional Information
AMBI Group (Borja et al., 2000)	III
Distribution References	Labourg & Lasserre, 1980, Barnes, 1973, Boyden, 1972, Boyden & Russel, 1972, Barnes, 1980b, Barnes, 1994, Brock, 1979, Rygg, 1970, Ansell et al., 1981, Seaward, 1982, Seaward, 1990, Anonymous, 1999(s)
Reproduction/Life History
Reproductive type	Gonochoristic	Developmental mechanism	Planktotrophic
Reproductive Season	May to July	Reproductive Location	Insufficient information
Reproductive frequency	Annual episodic	Regeneration potential	No
Life span	3-5 years	Age at reproductive maturity	Insufficient information
Generation time	Insufficient information	Fecundity	Insufficient information
Egg/propagule size	Insufficient information	Fertilization type	Insufficient information
Larvae/Juveniles Larval/Juvenile dispersal potential Insufficient information Larval settlement period Insufficient information Duration of larval stage 11-30 days
Additional Information	Veliger larvae have a pelagic life of from 11 to 30 days. Newly settled young attach temporarily by byssus threads to filamentous algae before becoming buried in the top few centimetres of sediment. Gametogenesis occurs in early spring and spawning takes place from May to July. Individuals live for about five years.
Reproduction References	Barnes, 1973, Rygg, 1970, Ansell et al., 1981