Description of biotope or habitat type
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Amphiura filiformis and Ennucula tenuis in circalittoral and offshore sandy mud
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Weak (>1 kn), Very weak (negligible) |
| Substratum | Sandy mud |
| Zone | Circalittoral |
| Depth Band | 10-20 m, 20-30 m |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna |
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
In cohesive and non-cohesive sandy mud, off moderately exposed coasts in deep water dense populations of Amphiura filiformis with the bivalve Ennucula tenuis may occur. This biotope together with SS.SMu.CSaMu.AfilKurAnit, SS.SMu.CSaMu.ThyEten and SS.SSa.OSa.OfusAfil may be part of the Amphiura filiformis dominated infralittoral etage described by Glemarec (1973) and part of the 'off-shore muddy sand association' described by other workers (Jones 1951; Mackie 1990). Other species characteristic of this biotope may include the echinoderms Ophiura albida and Echinocardium flavescens and the bivalve Kurtiella bidentata. Phaxas pellucidus, Owenia fusiformis and Virgularia mirabilismay also be present. At the sediment surface the hydroid Sertularia argentea may be present although only at very low abundances. Variations of this biotope exist in the northern North Sea (SS.SMu.CSaMu.AfilKurAnit) and it is possible that more than one entity exists for this biotope. Collectively the biotopes SS.SMu.CSaMu.ThyEten, SS.SMu.CSaMu.AfilKurAnit, SS.SMu.CSaMu.AfilEten, SS.SMu.OMu.PjefThyAfil, and SS.SSa.OSa.OfusAfil, may form the Amphiura dominated components of the 'off-shore muddy sand association' described by other workers (Jones 1951; Thorson 1957; Mackie 1990) and the infralittoral etage described by Glemarec (1973).
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Obelia longissima | 57 | Rare | 81-100% |
| Sertularia argentea | 26 | Rare | 61-80% |
| Amphiura filiformis | 22 | Super abundant | 81-100% |
| Ennucula tenuis | 15 | Common | 81-100% |
| Ophiura albida | 12 | Super abundant | 81-100% |
| Echinocardium flavescens | 10 | Abundant | 61-80% |
| Kurtiella bidentata | 9 | Common | 61-80% |
| Cellaria fistulosa | 8 | Rare | 41-60% |
| Hydrallmania falcata | 8 | Rare | 41-60% |
| Owenia fusiformis | 3 | Common | 41-60% |
| Phaxas pellucidus | 3 | Frequent | 61-80% |
| Virgularia mirabilis | 3 | Abundant | 41-60% |
| Abra nitida | 2 | 41-60% | |
| Antalis entalis | 2 | Frequent | 41-60% |
| Cylichna cylindracea | 2 | Common | 41-60% |
| Diplocirrus glaucus | 2 | 61-80% | |
| Lagis koreni | 2 | Common | 41-60% |
| Ophelina acuminata | 2 | Common | 41-60% |
| Scalibregma inflatum | 2 | 41-60% |
Similar biotopes or habitat types
SS.SMu.CSaMu.AfilKurAnit
SS.SMu.CSaMu.AfilEten may be distinguished from SS.SMu.CSaMu.AfilKurAnit by the abundance of the characterising species Ennucula tenuis in SS.SMu.CSaMu.AfilEten and by the importance of other characterising species such as Thysanocardia procera and Nephtys incise in SS.SMu.CSaMu.AfilKurAnit. SS.SMu.CSaMu.AfilEten is also generally found at greater depths and may be a deeper water extension of SS.SMu.CSaMu.AfilKurAnit.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMu.CSaMu.AfilNten | Amphiura filiformis and Nuculoma tenuis in circalittoral and offshore sandy mud |
| 2004 (04.05) | SS.SMu.CSaMu.AfilNten | Amphiura filiformis and Nuculoma tenuis in circalittoral and offshore sandy mud |
| 1997 (97.06) | Part of SS.CMS.AfilEcor | Amphiura filiformis and Echinocardium cordatum in circalittoral clean or slightly muddy sand |