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.
- 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.
Description
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.
Situation
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
SS.SSa.OSa.MalEdef
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 |