Description of biotope or habitat type
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Anemones, including Corynactis viridis, crustose sponges and colonial ascidians on very exposed or wave surged vertical infralittoral 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 |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 m, 10-20 m, 20-30 m |
| Other Features | Wave surged vertical rock; in surge gullies and caves. |
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
Vertical very exposed and exposed bedrock gullies, tunnels and cave entrances subject to wave-surge dominated by sponge crusts such as Clathrina coriacea, Myxilla incrustans, Pachymatisma johnstonia and Halichondria panicea and anthozoans such as Cylista elegans, Urticina felina, Alcyonium digitatum, Corynactis viridis and dwarf Metridium senile generally dominate the area; the anthozoans often appearing to protrude through the sponge layer. There may be dense aggregations of the hydroid Tubularia indivisa, the cup coral Caryophyllia smithii and the colonial ascidians Botrylloides leachii and Polyclinum aurantium. There may be a short crisiid turf, interspersed with Cradoscrupocellaria reptans. Encrusting coralline algae may occur on well-illuminated rock faces. The echinoderms Asterias rubens, Marthasterias glacialis, Echinus esculentus, Antedon bifida and Ophiothrix fragilis, the topshell Calliostona zizphinum and the calcareous tubeworm Spirobranchus triqueter may also be present on the rock face. The crabs Cancer pagurus and Necora puber may also be recorded. Due to the wave-surged nature and vertical orientation of these biotopes, kelps are rare and certainly never dominate.
Situation
No situation data available.
Temporal variation
Unknown.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Corynactis viridis | 14 | Common | 81-100% |
| Alcyonium digitatum | 5 | Occasional | 61-80% |
| Cylista elegans | 5 | Frequent | 61-80% |
| Asterias rubens | 4 | Occasional | 61-80% |
| Calliostoma zizyphinum | 4 | Occasional | 61-80% |
| Metridium senile | 4 | Frequent | 41-60% |
| Tubularia indivisa | 4 | Frequent | 61-80% |
| Corallinaceae | 3 | Frequent | 41-60% |
| Bryozoa indet crusts | 3 | Frequent | 41-60% |
| Cancer pagurus | 3 | Occasional | 61-80% |
| Clathrina coriacea | 3 | Occasional | 61-80% |
| Pachymatisma johnstonia | 3 | Occasional | 21-40% |
| Botrylloides leachii | 2 | Occasional | 41-60% |
| Caryophyllia smithii | 2 | Occasional | 41-60% |
| Crisiidae | 2 | Frequent | 41-60% |
| Didemnidae | 2 | Frequent | 21-40% |
| Myxilla incrustans | 2 | Frequent | 41-60% |
| Porifera indet crusts | 2 | Frequent | 41-60% |
| Cradoscrupocellaria reptans | 2 | Common | 41-60% |
| Echinus esculentus | 2 | Occasional | 41-60% |
| Antedon bifida | 1 | Occasional | 41-60% |
| Halichondria panicea | 1 | Frequent | 41-60% |
| Marthasterias glacialis | 1 | Occasional | 41-60% |
| Necora puber | 1 | Occasional | 41-60% |
| Ophiothrix fragilis | 1 | Occasional | 21-40% |
| Polyclinum aurantium | 1 | Frequent | 41-60% |
| Spirobranchus triqueter | 1 | Occasional | 21-40% |
| Urticina felina | 1 | Occasional | 41-60% |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code |
|---|---|
| 1996 (6.95) | ELR.BPat.Lpyg |
| 1995 | LRK.LPYG |