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information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

Lagoon cockle (Cerastoderma glaucum)

Distribution data supplied by the Ocean Biogeographic Information System (OBIS). To interrogate UK data visit the NBN Atlas.

Summary

Description

The cockle, Cerastoderma glaucum is a filter feeding bivalve which burrows shallowly in soft sediments. The species exists in two forms, a typical thin-shelled variety found in brackish lagoon habitats and a thicker shelled variety occurring in estuaries. It is widely distributed in north-west Europe.

Recorded distribution in Britain and 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.

Habitat

The species is found submerged in saline lagoons or more rarely on the low shore of estuaries. Adults usually burrow shallowly in soft sediments. The failure of the species to colonize the higher shore is believed to be due to an inability to tolerate aerial exposure and it's consequent conditions. The species' distribution is believed to be restricted by the damaging effect of wave action on the newly settled spat.

Depth range

Shallow

Identifying features

  • Rounded globular shell with 22-28 conspicuous radiating ribs.
  • Anterior margin of shell crenulate, posterior margin smooth.
  • Hinge line with cardinal and lateral teeth.
  • Adductor muscle scars roughly the same size.
  • Pallial sinus absent.

Additional information

No text entered

Listed by

Further information sources

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Biology review

Taxonomy

PhylumMollusca
ClassBivalvia
OrderVeneroida
FamilyCardiidae
GenusCerastoderma
Authority(Bruguière, 1789)
Recent SynonymsCardium lamarckii (Bruguière, 1789)

Biology

Typical abundanceLow density
Male size rangeUp to 5cm
Male size at maturity
Female size rangeSmall-medium(3-10cm)
Female size at maturity
Growth formBivalved
Growth rate9.6mm/year
Body flexibility
Mobility
Characteristic feeding methodActive suspension feeder, No information
Diet/food source
Typically feeds on
Sociability
Environmental positionInfaunal
DependencyNo information found.
SupportsNo information
Is the species harmful?No

Biology 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).

Habitat preferences

Physiographic preferencesEstuary, Isolated saline water (Lagoon)
Biological zone preferencesLower eulittoral, Sublittoral fringe
Substratum / habitat preferencesCoarse clean sand, Fine clean sand, Mud, Muddy sand, Sandy mud
Tidal strength preferencesWeak < 1 knot (<0.5 m/sec.)
Wave exposure preferencesSheltered, Very sheltered
Salinity preferencesLow (<18 psu), Variable (18-40 psu)
Depth rangeShallow
Other preferencesNo text entered
Migration PatternNon-migratory / resident

Habitat 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).

Life history

Adult characteristics

Reproductive typeGonochoristic (dioecious)
Reproductive frequency Annual episodic
Fecundity (number of eggs)No information
Generation timeInsufficient information
Age at maturityInsufficient information
SeasonMay - July
Life span2-5 years

Larval characteristics

Larval/propagule type-
Larval/juvenile development Planktotrophic
Duration of larval stage11-30 days
Larval dispersal potential No information
Larval settlement periodInsufficient information

Life history 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.

Sensitivity reviewHow is sensitivity assessed?

Physical pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
High Low High Low
Cerastoderma glaucum lives embedded within the substratum and would be removed upon substratum loss. The species has slow recovery due to its restricted distribution.
High Low High Low
Bivalves have rather limited ability to burrow upwards so the species would be buried upon smothering. Cerastoderma glaucum has slow recovery due to it's restricted distribution.
Tolerant Not relevant Not sensitive Low
The species is probably tolerant of siltation because it lives in estuaries and lagoons where siltation frequently occurs.
No information
High Low High Moderate
The low shore position of Cerastoderma glaucum suggests that it has a low tolerance of desiccation. Boyden (1972) observed that the species can tolerate 33 percent water loss and that death occurs between 33 and 38 percent water loss. Recovery would be low due to the restricted distribution of this species.
High Low High Low
The low shore position of Cerastoderma glaucum suggests that its has an inability to tolerate exposure to air and it's consequent conditions. Unlike Cerastoderma edule the shells of Cerastoderma glaucum remain closed upon exposure to air. The species may suffer desiccation, increased metabolic cost and exposure to predation by birds. Recovery would be low due to the restricted distribution of this species.
No information
Intermediate Low High Very low
The species and its preferred habitat could be washed away by increased water flow rate. Recovery would be slow due to the restricted distribution of the species.
No information
Low High Low Moderate
Cerastoderma glaucum can tolerate a wide range of temperatures. Populations have been observed to survive in lagoons in conditions from almost freezing to more than 30 degree C. However, a high mortality of cockles was observed in South East England after the exceptionally cold winter of 1962/3. Boyden (1972) observed that Cerastoderma glaucum has a LD50 of 62.3 hours at 20 degrees C in air.
No information
Low High Low Low
The species is a suspension feeder so may benefit from increased turbidity by a greater food supply. However, if turbidity is caused by silt particles additional feeding costs would be imposed.
No information
High Low High Low
It has been suggested that the juveniles of Cerastoderma glaucum are very intolerant of wave exposure which controls the species' distribution. The species is restricted to sheltered sites which suggests it is intolerant of increased wave exposure. Increased wave exposure may also remove the species preferred habitat. Recovery would be low due to the species' limited distribution.
No information
No information Not relevant No information Not relevant
Insufficient
information
No information Not relevant No information Not relevant
Insufficient
information
Intermediate Moderate Moderate Very low
The shells of Cerastoderma glaucum are rather thin and brittle, so it is probably quite intolerant of abrasion.
Tolerant Very high Not sensitive Moderate
The species is not sensitive to displacement. A population of Cerastoderma glaucum established itself in Emsworth Harbour by displacement of animals from adjacent lagoon habitats (Barnes, 1973).

Chemical pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
No information No information No information Not relevant
Insufficient
information
Heavy metal contamination
No information No information No information Not relevant
Insufficient
information
Hydrocarbon contamination
No information No information No information Not relevant
Insufficient
information
Radionuclide contamination
No information Not relevant No information Not relevant
Insufficient
information
Changes in nutrient levels
Intermediate Low High Low
An increase in nutrients may lead to eutrophication and reduced oxygen levels. Juveniles of the species are very intolerant of reduced oxygen concentration. Recovery would be low due to the restricted distribution of this species.
Low High Low Moderate
The species can survive in lagoons where salinity varies from 7 psu to 84 psu, so it has a high tolerance of different salinities.
No information
High Low High Moderate
Juveniles of Cerastoderma glaucum are very intolerant of low oxygen concentrations. However adults can survive for 84 hours in oxygen free water (Boyden, 1972).

Biological pressures

 IntoleranceRecoverabilitySensitivityEvidence/Confidence
No information Not relevant No information Not relevant
Insufficient
information
No information Not relevant No information Not relevant
Insufficient
information
No information Not relevant No information Not relevant
Insufficient
information
No information Not relevant No information Not relevant
Insufficient
information

Additional information

None

Importance review

Policy/legislation

Northern Ireland Priority Species

Status

Non-native

Importance information

The species is harvested in Yugoslavia for human consumption, and may be harvested elsewhere.

Bibliography

  1. Anonymous, 1999s. Saline lagoons. Habitat Action Plan. In UK Biodiversity Group. Tranche 2 Action Plans. English Nature for the UK Biodiversity Group, Peterborough., English Nature for the UK Biodiversity Group, Peterborough.

  2. Ansell, A.D., Barnett, P.R.O., Bodoy, A. & Masse, H., 1981. Upper temperature tolerances of some European Mollusca III. Cardium glaucum, C. tuberculata and C. edule. Marine Biology, 65, 177-183.

  3. Barnes, R.S.K., 1973. The intertidal lamellibranchs of Southampton Water, with particular reference to Cerastoderma edule and C. glaucum. Proceedings of the Malacological Society of London, 40, 413-433.

  4. Barnes, R.S.K., 1980b. Coastal lagoons. The natural history of a neglected habitat. Cambridge: Cambridge University Press.

  5. Barnes, R.S.K., 1994. The brackish-water fauna of northwestern Europe. Cambridge: Cambridge University Press.

  6. Boyden, C.R. & Russel, P.J.C., 1972. The distribution and habitat range of the brackish water cockle (Cardium (Cerastoderma) edule) in the British Isles. Journal of Animal Ecology, 41, 719-734.

  7. Boyden, C.R., 1972. Behaviour, survival and respiration of the cockles Cerastoderma edule and C. glaucum in air. Journal of the Marine Biological Association of the United Kingdom, 52, 661-680.

  8. Brock, V., 1979. Habitat selection of two congeneric bivalves, Cardium edule and C. glaucum in sympatric and allopatric populations. Marine Biology, 54, 149-156.

  9. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]

  10. Labourg, P.J., Lasserre, G., 1980. Population Dynamics of Cerastoderma glaucum in an Artificial Lagoon of the Arcachon Region. Marine Biology, 60, 147-157.

  11. Rygg, B., 1970. Studies on Cerastoderma edule (L.) and Cerastoderma glaucum (Poiret). Sarsia, 43, 65-80.

  12. Seaward, D.R., 1982. Sea area atlas of the marine molluscs of Britain and Ireland. Peterborough: Nature Conservancy Council.

  13. Seaward, D.R., 1990. Distribution of marine molluscs of north west Europe. Peterborough: Nature Conservancy Council.

Citation

This review can be cited as:

White, N. 2002. Cerastoderma glaucum Lagoon cockle. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. Available from: http://www.marlin.ac.uk/species/detail/1315

Last Updated: 15/07/2002