Description of biotope or habitat type
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Circalittoral muddy sand
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Fine to very fine sand with a fine silt fraction |
| 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
Circalittoral non-cohesive muddy sands with the silt content of the substratum typically ranging from 5% to 20%. This habitat is generally found in water depths of over 15-20m and supports animal-dominated communities characterised by a wide variety of polychaetes, bivalves such as Abra alba and Nucula nitidosa, and echinoderms such as Amphiura spp and Ophiura spp., and Astropecten irregularis. These circalittoral habitats tend to be more stable than their infralittoral counterparts and as such support a richer infaunal community.
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 |
|---|---|---|---|
| Acrocnida brachiata | 18 | Common | 61-80% |
| Asterias rubens | 14 | Occasional | 61-80% |
| Abra alba | 12 | Abundant | 81-100% |
| Nucula nitidosa | 11 | Frequent | 81-100% |
| Pagurus bernhardus | 8 | Occasional | 61-80% |
| Fabulina fabula | 7 | Common | 61-80% |
| Astropecten irregularis | 6 | Occasional | 41-60% |
| Chaetozone setosa | 6 | Common | 61-80% |
| Ophiura ophiura | 6 | Occasional | 41-60% |
| Spiophanes bombyx | 6 | Frequent | 61-80% |
| Echinocardium cordatum | 5 | Rare | 41-60% |
| Metridium senile | 5 | Rare | 21-40% |
| Nephtys | 5 | Common | 61-80% |
| Lanice conchilega | 4 | Occasional | 41-60% |
| Scoloplos armiger | 3 | 61-80% | |
| Pomatoschistus minutus | 3 | Occasional | 21-40% |
| Abra prismatica | 2 | Frequent | 41-60% |
| Corystes cassivelaunus | 2 | Occasional | 21-40% |
| Goniada maculata | 2 | 41-60% | |
| Lanice conchilega | 2 | 41-60% | |
| Liocarcinus depurator | 2 | Rare | 21-40% |
| Macropodia rostrata | 2 | Rare | 21-40% |
| Nemertea | 2 | 41-60% | |
| Nephtys hombergii | 2 | Common | 41-60% |
| Ophiura albida | 2 | Occasional | 21-40% |
| Owenia fusiformis | 2 | 41-60% | |
| Philine aperta | 2 | Occasional | 21-40% |
| Scalibregma inflatum | 2 | 41-60% | |
| Solenidae | 2 | Super abundant | 21-40% |
| Bathyporeia tenuipes | 1 | 41-60% | |
| Cerianthus lloydii | 1 | Frequent | 41-60% |
| Chamelea gallina | 1 | 41-60% | |
| Corystes cassivelaunus | 1 | 41-60% | |
| Gari fervensis | 1 | 41-60% | |
| Oestergrenia digitata | 1 | Occasional | 21-40% |
| Ophiura albida | 1 | Abundant | 41-60% |
| Prionospio fallax | 1 | 41-60% | |
| Cylista undata | 1 | Occasional | 21-40% |
| Sthenelais limicola | 1 | 41-60% | |
| Seraphsidae | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SSa.CMuSa | Circalittoral muddy sand |
| 2004 (04.05) | SS.SSa.CMuSa | Circalittoral muddy sand |
| 1997 (97.06) | Part of SS.CMS | Circalittoral muds |