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Marine Habitat Classification

Description of biotope or habitat type

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   Owenia fusiformis and Amphiura filiformis in offshore circalittoral sand or muddy sand

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure
Tidal streams
Substratum Slightly muddy sand.
Zone Circalittoral
Depth Band
Other Features

Biotope origin

Derived using data from Day Grab
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.OSa.OfusAfil <I>Owenia fusiformis</I> and <I>Amphiura filiformis</I> in offshore circalittoral 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.


Areas of slightly muddy sand (generally <20% mud) in offshore waters may be characterised by high numbers of the tube building oweniid polychaete Owenia fusiformis and Galathowenia sp., often with the brittlestar Amphiura filiformis. Whilst O. fusiformis is also found in other circalittoral or offshore biotopes it usually occurs in lower abundances than in SS.SSa.OSa.OfusAfil. Other species found in this community are the polychaetes Goniada maculata, Pholoe inornata, Diplocirrus glaucus, Chaetozone setosa and Spiophanes kroyeri with occasional bivalves such as Timoclea ovata and Thyasira equalis. The sea cucumber Labidoplax buski and the cumacean Eudorella truncatula are also commonly often found in this biotope. This biotope along with SS.SMu.CSaMu.ThyEten, SS.SMu.CSaMu.AfilKurAnit, SS.SMu.CSaMu.AfilEten and SS.SMu.OMu.PjefThyAfil, may comprise the Amphiura dominated components of the 'offshore muddy sand association' (Jones 1951; Mackie 1990) and the infralittoral etage described by Glemarec (1973). Variants of the biotope may contain the characteristic high numbers of Owenia fusiformis and Amphiura filiformis, but may also include Arctica islandica and Ennucula tenuis. Where these occur, the biotope may be considered a transitionary variant between SS.SSa.OSa.OfusAfil and SS.SMu.CSaMu.AfilKurAnit.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) % of core records where taxon was recorded Relative frequency %
Galathowenia oculata 11 1-20% 17.1
Owenia fusiformis 8 1-20% 10.9
Nemertea 8 1-20% 2.6
Phoronis 6 1-20% 1.6
Amphiura filiformis 5 1-20% 5
Scoloplos 4 1-20% 1.7
Notomastus 4 1-20% 1.3
Goniada maculata 4 1-20% 1
Paramphinome jeffreysii 3 1-20% 2.7
Chaetozone setosa 3 1-20% 1.3
Spiophanes kroyeri 3 1-20% 1.3
Copepoda 2 1-20% 2.1
Thyasira flexuosa 2 1-20% 1.6
Echinocyamus pusillus 2 1-20% 1.5
Diplocirrus glaucus 2 1-20% 1.3
Spiophanes bombyx 2 1-20% 0.8
Antalis entalis 2 1-20% 0.8
Phaxas pellucidus 2 1-20% 0.5
Kurtiella bidentata 1 1-20% 1.3
Hilbigneris gracilis 1 1-20% 1.1
Labidoplax buskii 1 1-20% 0.9
Trichobranchus roseus 1 1-20% 0.8
Mediomastus fragilis 1 1-20% 0.7
Edwardsia claparedii 1 1-20% 0.7
Glycera alba 1 1-20% 0.6
Paradoneis lyra 1 1-20% 0.6
Glycera lapidum 1 1-20% 0.6
Anobothrus gracilis 1 1-20% 0.6
Aonides paucibranchiata 1 1-20% 0.5
Aricidea 1 1-20% 0.5
Ennucula tenuis 1 1-20% 0.5
Terebellides stroemiii 1 1-20% 0.5
Nephtys hombergii 1 1-20% 0.4
Chaetoderma nitidulum 1 1-20% 0.3
Nephtys longosetosa 1 1-20% 0.3
Sthenelais limicola 1 1-20% 0.3

Similar biotopes or habitat types

Maldanid polychaetes may also occur in the current biotope but never in the same abundance as in SS.SSa.OSa.MalEdef.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SSa.OSa.OfusAfil Owenia fusiformis and Amphiura filiformis in offshore circalittoral sand or muddy sand
2004 (04.05) SS.SSa.OSa.OfusAfil Owenia fusiformis and Amphiura filiformis in offshore circalittoral sand or muddy sand
1997 (97.06) Part of SS.CMS.AfilEcor Amphiura filiformis and Echinocardium cordatum in circalittoral clean or slightly muddy sand

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