Description of biotope or habitat type
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Echinoderms and crustose communities
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) |
| Substratum | Bedrock, boulders |
| Zone | Circalittoral - lower, Circalittoral - upper |
| 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 complex occurs on wave-exposed, moderately strong to weakly tide-swept, circalittoral bedrock and boulders. Echinoderms, faunal (Parasmittina trispinosa) and algal crusts (red encrusting algae) dominate this biotope, giving a sparse appearance. Typical echinoderms present are the starfish Asterias rubens, the brittlestar Ophiothrix fragilis and the sea urchin Echinus esculentus. There may be isolated clumps of the hydroids Nemertesia antennina and Abietinaria abietina, Alcyonium digitatum, the anemone Urticina felina and the cup coral Caryophyllia smithii. Other species present may include the polychaete Spirobranchus triqueter and the top shell Calliostoma zizphinum. Five biotopes have been identified within this biotope complex: CarSwi, CarSp, FaAlCr, UrtScr and AdigVT.
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
| Taxon | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|
| Abietinaria abietina | Occasional | 41-60% |
| Alcyonium digitatum | Frequent | 81-100% |
| Asterias rubens | Occasional | 61-80% |
| Calliostoma zizyphinum | Occasional | 41-60% |
| Caryophyllia smithii | Frequent | 41-60% |
| Corallinaceae | Common | 61-80% |
| Echinus esculentus | Frequent | 81-100% |
| Nemertesia antennina | Occasional | 41-60% |
| Ophiothrix fragilis | Frequent | 41-60% |
| Parasmittina trispinosa | Frequent | 41-60% |
| Spirobranchus triqueter | Frequent | 41-60% |
| Urticina felina | Occasional | 41-60% |
Similar biotopes or habitat types
Not applicable or unknown.