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.
Amphiura filiformis, Kurtiella bidentata and Abra nitida in circalittoral sandy mud
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed |
| Tidal streams | Very weak (negligible) |
| Substratum | Sandy mud |
| Zone | Circalittoral |
| Depth Band | 50-100 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.
- 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
Cohesive sandy mud off wave exposed coasts with weak tidal streams can be characterised by super-abundant Amphiura filiformis with Kurtiella bidentata and Abra nitida. This community occurs in muddy sands in moderately deep water (Hiscock 1984; Picton et al. 1994) and may be related to the 'offshore muddy sand association' described by other workers (Jones 1951; Thorson 1957; Mackie 1990). This community is also characterised by the sipunculid Thysanocardia procera and the polychaetes Nephtys incisa, Phoronis sp. and Pholoe sp., with cirratulids, such as Notomastus latericeus or Mediomastus fragilis, and terebellids, such as Polycirrus plumosus or Diplocirrus glaucus, also common in some areas. Other taxa such as Nephtys hombergii, Echinocardium cordatum, Nucula nitidosa, Callianassa subterranea and Eudorella truncatula may also occur in offshore examples of this biotope. Additionally, several variants of this biotope can be described in transitionary environments between biotopes such as SS.SMx.CMx.KurThyMx where coarser material is present, SS.SSa.OSa.OfusAfil in sandier environments offshore or SS.SMu.ISaMu.MelMagThy in shallower waters. 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 (%) | % of core records where taxon was recorded | Relative frequency % |
|---|---|---|---|
| Amphiura filiformis | 18 | 1-20% | 20.3 |
| Kurtiella bidentata | 12 | 1-20% | 13.6 |
| Hilbigneris gracilis | 5 | 1-20% | 1.3 |
| Nephtys hombergii | 4 | 1-20% | 0.9 |
| Diplocirrus glaucus | 4 | 1-20% | 0.9 |
| Cylichna cylindracea | 4 | 1-20% | 0.7 |
| Abra nitida | 3 | 1-20% | 1.8 |
| Pholoe inornata | 3 | 1-20% | 0.7 |
| Thysanocardia procera | 3 | 1-20% | 0.5 |
| Owenia fusiformis | 3 | 1-20% | 0.5 |
| Nemertea | 3 | 1-20% | 0.5 |
| Scalibregma inflatum | 2 | 1-20% | 1.2 |
| Thyasira flexuosa | 2 | 1-20% | 0.5 |
| Callianassa subterranea | 2 | 1-20% | 0.3 |
| Echinocardium cordatum | 2 | 1-20% | 0.3 |
| Spisula subtruncata | 1 | 1-20% | 5 |
| Tubularia | 1 | 1-20% | 1.1 |
| Nucula nitidosa | 1 | 1-20% | 0.8 |
| Phoronis | 1 | 1-20% | 0.6 |
| Melinna palmata | 1 | 1-20% | 0.6 |
| Chaetozone setosa | 1 | 1-20% | 0.5 |
| Notomastus latericeus | 1 | 1-20% | 0.5 |
| Phoronis muelleri | 1 | 1-20% | 0.5 |
| Virgularia mirabilis | 1 | 1-20% | 0.3 |
| Nephtys incisa | 1 | 1-20% | 0.3 |
| Phaxas pellucidus | 1 | 1-20% | 0.3 |
| Cerebratulus | 1 | 1-20% | 0.2 |
| Leptosynapta inhaerens | 1 | 1-20% | 0.2 |
| Amphictene auricoma | 1 | 1-20% | 0.2 |
| Ampharete lindstroemi | 1 | 1-20% | 0.2 |
| Anobothrus gracilis | 1 | 1-20% | 0.2 |
| Varicorbula gibba | 1 | 1-20% | 0.2 |
| Edwardsia claparedii | 1 | 1-20% | 0.2 |
| Cerianthus lloydii | 1 | 1-20% | 0.2 |
| Ophiura ophiura | 1 | 1-20% | 0.2 |
| Lagis koreni | 1 | 1-20% | 0.2 |
| Glycera tridactyla | 1 | 1-20% | 0.1 |
Similar biotopes or habitat types
SS.SSa.CMuSa.AalbNuc
In sandier sediments SS.SMu.CSaMu.AfilKurAnit may grade into SS.SSa.CMuSa.AalbNuc.
SS.SSa.IMuSa.FfabMag
In shallower sandy sediments SS.SMu.CSaMu.AfilKurAnit may grade into SS.SSa.IMuSa.FfabMag.
SS.SMu.CSaMu.AfilEten
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 in deeper water.
SS.SMu.CSaMu.ThyEten
SS.SMu.CSaMu.ThyEten may be distinguished from SS.SMu.CSaMu.AfilKurAnit by the abundance of the characterising species Thyasira flexuosa and by the decreased abundance of Amphiura filiformis in SS.SMu.CSaMu.ThyEten. SS.SMu.CSaMu.ThyEten is generally found in deeper waters.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMu.CSaMu.AfilMysAnit | Amphiura filiformis, Mysella bidentata and Abra nitida in circalittoral sandy mud |
| 2004 (04.05) | SS.SMu.CSaMu.AfilMysAnit | Amphiura filiformis, Mysella bidentata and Abra nitida in circalittoral sandy mud |
| 1997 (97.06) | Part of SS.CMS.AfilEcor and SS.IMS.FaMS.SpiSpi | Amphiura filiformis and Echinocardium cordatum in circalittoral clean or slightly muddy sand and Spio filicornis and Spiophanes bombyx in infralittoral clean or muddy sand |