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Marine Habitat Classification

Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Arenicola marina in infralittoral fine sand or muddy sand

Physical habitat description

Salinity Full (30-35 ppt), Variable (18-35 ppt)
Wave exposure Moderately exposed, Sheltered, Very sheltered, Extremely sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible)
Substratum Fine to very fine sand and muddy sand
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 m
Other Features

Biotope origin

Derived using data from Various
Faunal group Infauna

Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.

Distribution of habitat SS.SSa.IMuSa.AreISa <I>Arenicola marina</I> in infralittoral fine sand or muddy sand

  • Records used to define the biotope (core records)
  • Other records assigned to this biotope, marked as 'certain'
  • Other records assigned to this biotope, marked as 'uncertain'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.


In shallow fine sand or non-cohesive muddy sand in fully marine conditions (or occasionally in variable salinity) a community characterised by the polychaete Arenicola marina may occur. This biotope appears quite faunally sparse. Taxa present, however, include scavenging crustaceans such as Pagurus bernhardus and Liocarcinus depurator, terebellid polychaetes such as Lanice conchilega and the burrowing anemone Cerianthus lloydii. Occasional Sabella pavonina and frequent Ensis spp. may also be observed in some areas. The majority of records for this biotope are derived from epifaunal surveys and consequently there is little information available for the associated infaunal species. It is possible that this biotope, like SS.SSa.IMuSa.EcorEns (to which it is broadly similar) is an epibiotic overlay on other biotopes from the SSa complex.


No situation data available.

Temporal variation

At certain times of the year a diatom film may be present on the sediment surface.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Capitella capitata 91 Common 61-80%
Arenicola marina 55 Common 81-100%
Pagurus bernhardus 10 Occasional 61-80%
Diatoms - film 9 Common 21-40%
Arenicola marina 9 Abundant 61-80%
Lanice conchilega 5 Occasional 41-60%
Carcinus maenas 2 Occasional 21-40%
Cerianthus lloydii 2 Frequent 21-40%
Liocarcinus depurator 2 Occasional 21-40%
Ensis 1 Frequent 21-40%
Hydractinia echinata 1 Occasional 21-40%
Sabella pavonina 1 Occasional 21-40%
Seraphsidae 1 Occasional 21-40%

Similar biotopes or habitat types

SS.SSa.IMuSa.AreISa is likely to be a shallow water extension of the littoral Arenicola biotope LS.LSa.MuSa.MacAre.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SSa.IMuSa.AreISa Arenicola marina in infralittoral fine sand or muddy sand
2004 (04.05) SS.SSa.IMuSa.AreISa Arenicola marina in infralittoral fine sand or muddy sand

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