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.
Circalittoral Sabellaria reefs (on rock)
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn) |
| Substratum | Bedrock, boulders, cobbles, pebbles |
| Zone | Circalittoral - lower |
| Depth Band | 10-20 m, 20-30 m |
| Other Features |
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
This biotope complex occurs on moderately wave-exposed, circalittoral bedrock, boulders and cobbles subject to moderately strong tidal streams. It is characterised by dense crusts of the polychaete Sabellaria spinulosa covering the substratum. Other fauna present in many cases reflects the biotopes found on nearby rock, so to a certain extent, is quite variable. Species typically present include the bryozoans Flustra foliacea, Alcyonidium diaphanum and Pentapora foliacea, the hydroid Nemertesia antennina, the sponges Tethya aurantium and Phorbas fictitius, the anemones Urticina felina and Cylista elegans, and the ascidians Distomus variolosus, Polycarpa pomaria and Polycarpa scuba. The barnacle Balanus crenatus, the polychetes Spirobranchus triqueter and Salmacina dysteri, the starfish Crossaster papposus, and Alcyonium digitatum may also be recorded. Two variants of the Sspi biotope have been identified: Sspi.ByB and Sspi.As (characterised by didemnid ascidians).
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Sabellaria spinulosa | 32 | Common | 81-100% |
| Didemnidae | 10 | Frequent | 41-60% |
| Flustra foliacea | 8 | Occasional | 61-80% |
| Asterias rubens | 7 | Occasional | 61-80% |
| Urticina felina | 5 | Occasional | 41-60% |
| Alcyonium digitatum | 3 | Frequent | 21-40% |
| Distomus variolosus | 3 | Common | 21-40% |
| Spirobranchus triqueter | 3 | Frequent | 21-40% |
| Crossaster papposus | 2 | Occasional | 21-40% |
| Pentapora foliacea | 2 | Occasional | 21-40% |
| Polycarpa pomaria | 2 | Common | 21-40% |
| Alcyonidium diaphanum | 1 | Occasional | 21-40% |
| Balanus crenatus | 1 | Frequent | 21-40% |
| Nemertesia antennina | 1 | Occasional | 21-40% |
| Phorbas fictitius | 1 | Occasional | 21-40% |
| Polycarpa scuba | 1 | Common | 21-40% |
| Cylista elegans | 1 | Occasional | 21-40% |
| Salmacina dysteri | 1 | Occasional | 21-40% |
| Tethya aurantium | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1997 (97.06) | CR.MCR.CSab |