Description of biotope or habitat type
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Abra alba and Nucula nitidosa in circalittoral muddy sand or slightly mixed sediment
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn) |
| Substratum | Fine muddy sands occasionally with small gravel content |
| Zone | Circalittoral |
| Depth Band | 10-20 m, 20-30 m, 30-50 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
Non-cohesive muddy sands or slightly shelly/gravelly muddy sand characterised by the bivalves Abra alba and Nucula nitidosa. Other important taxa include Nephtys spp., Chaetozone setosa and Spiophanes bombyx with Fabulina fabula also common in many areas. The echinoderms Ophiura albida and Asterias rubens may also be present. The epibiotic biotope SS.SSa.IMuSa.EcorEns may overlap this biotope. This biotope is part of the Abra community defined by Thorson (1957) and the infralittoral etage described by Glemarec (1973). In organically enriched variants of this biotope, there may be higher occurrences of amphipods, such as Bathyporeia tenuipes, Perioculodes longimanus, and Urothoe elegans.
Situation
No situation data available.
Temporal variation
Numbers of adult Abra alba can exceed 1000 m2.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | % of core records where taxon was recorded | Relative frequency % |
|---|---|---|---|
| Abra alba | 12 | 1-20% | 17.8 |
| Hilbigneris gracilis | 5 | 1-20% | 2.2 |
| Nemertea | 5 | 1-20% | 2.1 |
| Aricidea | 4 | 1-20% | 2.2 |
| Nucula nitidosa | 4 | 1-20% | 1.8 |
| Actiniaria | 4 | 1-20% | 5.2 |
| Poecilochaetus serpens | 3 | 1-20% | 1.1 |
| Varicorbula gibba | 3 | 1-20% | 9.5 |
| Spiophanes bombyx | 3 | 1-20% | 0.8 |
| Spio decorata | 2 | 1-20% | 0.9 |
| Nephtys hombergii | 2 | 1-20% | 0.7 |
| Phaxas pellucidus | 2 | 1-20% | 1.6 |
| Chaetozone setosa | 2 | 1-20% | 1.8 |
| Glycera tridactyla | 2 | 1-20% | 0.9 |
| Magelona filiformis | 2 | 1-20% | 1.5 |
| Bathyporeia tenuipes | 2 | 1-20% | 1.7 |
| Magelona minuta | 2 | 1-20% | 1.1 |
| Nephtys | 2 | 1-20% | 0.4 |
| Owenia fusiformis | 1 | 1-20% | 0.3 |
| Ampelisca spinipes | 1 | 1-20% | 2.2 |
| Lanice conchilega | 1 | 1-20% | 0.4 |
| Sthenelais | 1 | 1-20% | 0.4 |
| Scalibregma inflatum | 1 | 1-20% | 1.8 |
| Echinocyamus pusillus | 1 | 1-20% | 0.6 |
| Liocarcinus | 1 | 1-20% | 0.3 |
| Phoronis | 1 | 1-20% | 0.3 |
| Magelona alleni | 1 | 1-20% | 0.3 |
| Chaetozone | 1 | 1-20% | 1 |
| Chamelea gallina | 1 | 1-20% | 0.3 |
| Perioculodes longimanus | 1 | 1-20% | 0.5 |
| Urothoe elegans | 1 | 1-20% | 0.9 |
| Pontocrates altamarinus | 1 | 1-20% | 0.3 |
| Pagurus | 1 | 1-20% | 0.2 |
| Eudorella truncatula | 1 | 1-20% | 0.7 |
| Parexogone hebes | 1 | 1-20% | 0.4 |
| Amphipholis squamata | 1 | 1-20% | 1.2 |
| Lagis koreni | 1 | 1-20% | 0.7 |
| Ampharete lindstroemi | 1 | 1-20% | 0.4 |
| Harpinia antennaria | 1 | 1-20% | 0.7 |
| Bathyporeia elegans | 1 | 1-20% | 1.5 |
| Exogone | 1 | 1-20% | 0.3 |
| Eumida bahusiensis | 1 | 1-20% | 0.2 |
| Pseudopolydora pulchra | 1 | 1-20% | 0.3 |
| Megaluropus agilis | 1 | 1-20% | 0.3 |
Similar biotopes or habitat types
SS.SMu.CSaMu.AfilKurAnit
In muddier sediments SS.SSa.CMuSa.AalbNuc may grade into SS.SMu.CSaMu.AfilKurAnit.
SS.SMu.CFiMu.BlyrAchi
At greater depths and in muddier sediments SS.SSa.CMuSa.AalbNuc may grade into SS.SMu.CFiMu.BlyrAchi.
SS.SMu.CSaMu.LkorPpel
In muddier sediments SS.SSa.CMuSa.AalbNuc may grade into SS.SMu.CSaMu.LkorPpel.
SS.SSa.IMuSa.FfabMag
The two biotopes may be separated by the relative dominance of Abra alba and Nucula spp. in SS.SSa.CMuSa.AalbNuc and the increased proportion of amphipods such as Bathyporeia spp.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SSa.CMuSa.AalbNuc | Abra alba and Nucula nitidosa in circalittoral muddy sand or slightly mixed sediment |
| 2004 (04.05) | SS.SSa.CMuSa.AalbNuc | Abra alba and Nucula nitidosa in circalittoral muddy sand or slightly mixed sediment |
| 1997 (97.06) | SS.CMS.AbrNucCor | Abra alba, Nucula nitida and Corbula gibba in circalittoral muddy sand or slightly mixed sediment |