Description of biotope or habitat type
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Caryophyllia smithii, sponges and crustose communities on wave-exposed circalittoral rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Extremely exposed, Very exposed, Exposed, Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock, boulders |
| Zone | Circalittoral |
| Depth Band | 10-20 m, 20-30 m, 30-50 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 typically occurs on the upper and vertical faces of wave-exposed, moderately strong to weakly tide-swept, circalittoral bedrock or boulders, with a water depth range of 20-30m. This often silty biotope has a typically sparse fauna, appearing grazed, and is characterised by common cup corals Caryophyllia smithii, frequent Alcyonium digitatum and occasional urchins Echinus esculentus. There may be occasional large growths of the sponge Cliona celata, Haliclona viscosa, Pachymatisma johnstonia and the axinellid sponge Stelligera stuposa. Echinoderms form a prominent feature of the fauna within this biotope, with species such as Marthasterias glacialis, Asterias rubens, Luidia ciliaris, Henricia oculata, Holothuria (Panningothuria) forskali, Antedon bifida and Aslia lefevrei present. Bryozoan crusts such as Parasmittina trispinosa and encrusting red algae cover the rock/boulder surface. The bryozoan Porella compressa may also be recorded occasionally. Isolated clumps of hydroids feature species such as Nemertesia antennina, Nemertesia ramosa, Abietinaria abietina, Halecium halecinum and Sertularella gayi. Other species observed include the anemone Corynactis viridis, Urticina felina, Cylista elegans, Calliostoma zizyphinum, Balanus crenatus and Spirobranchus triqueter. Two variants within this biotope have been distinguished: CarSp.PenPcom and CarSp.Bri. While CarSp.PenPcom tends to have the bryozoans Pentapora foliacea and P. compressa, while CarSp.Bri features a dynamic community of brittlestars covering the seabed in a dense mat. Ophiothrix fragilis is usually the dominant species in shallow water but tends to be replaced by Ophiocomina nigra in deeper water.
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 |
|---|---|---|---|
| Caryophyllia smithii | 9 | Frequent | 81-100% |
| Alcyonium digitatum | 6 | Frequent | 81-100% |
| Cliona celata | 6 | Frequent | 81-100% |
| Echinus esculentus | 6 | Occasional | 81-100% |
| Asterias rubens | 4 | Occasional | 61-80% |
| Corynactis viridis | 4 | Frequent | 61-80% |
| Marthasterias glacialis | 4 | Occasional | 61-80% |
| Parasmittina trispinosa | 4 | Frequent | 61-80% |
| Calliostoma zizyphinum | 3 | Occasional | 61-80% |
| Haliclona viscosa | 3 | Occasional | 61-80% |
| Henricia oculata | 3 | Occasional | 61-80% |
| Luidia ciliaris | 3 | Occasional | 61-80% |
| Nemertesia antennina | 3 | Occasional | 61-80% |
| Corallinaceae | 2 | Frequent | 41-60% |
| Abietinaria abietina | 2 | Frequent | 41-60% |
| Antedon bifida | 2 | Frequent | 41-60% |
| Aslia lefevrei | 2 | Occasional | 41-60% |
| Holothuria (Panningothuria) forskali | 2 | Occasional | 41-60% |
| Nemertesia ramosa | 2 | Occasional | 41-60% |
| Urticina felina | 2 | Occasional | 41-60% |
| Balanus crenatus | 1 | Frequent | 41-60% |
| Halecium halecinum | 1 | Occasional | 41-60% |
| Pachymatisma johnstonia | 1 | Occasional | 41-60% |
| Spirobranchus triqueter | 1 | Occasional | 41-60% |
| Porella compressa | 1 | Occasional | 21-40% |
| Cylista elegans | 1 | Occasional | 41-60% |
| Sertularella gayi | 1 | Occasional | 41-60% |
| Stelligera stuposa | 1 | Occasional | 41-60% |
Similar biotopes or habitat types
Not applicable or unknown.
