Description of biotope or habitat type
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Brachiopod and ascidian communities
Physical habitat description
| Salinity | Full (30-35 ppt), Reduced (18-30ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered |
| Tidal streams | Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock, boulders |
| Zone | Circalittoral - lower, Circalittoral - upper |
| Depth Band | 5-10 m, 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 the wave-sheltered, circalittoral bedrock and boulders subject to weak tidal streams. The biotopes within this complex are typically found in the Scottish sealochs (with the exception of LgAsSp, recorded off Ireland) and are characterised by brachipod and ascidian communities. Ascidians often recorded in this complex are Ciona intestinalis, Ascidia mentula, Ascidia virginea and Clavelina lepadiformis. The brachiopod Novocrania anomala is also characteristic of the biotopes within this complex recorded in Scottish sealochs. The polychaete Spirobranchus triqueter, the saddle oyster Pododesmus patelliformis, the cup coral Caryophyllia smithii and encrusting red algae are frequently recorded on the rocky substrata. Echinoderms such as the brittlestars Ophiothrix fraglis, Ophiocomina nigra and Ophiura albida, the starfish Asterias rubens, Crossaster papposus and Henricia oculata, the crinoid Antedon bifida and the urchin Echinus esculentus are all found in this complex. Other species present include the squat lobster Munida rugosa, the hermit crab Pagurus bernhardus, Alcyonium digitatum, the anemone Protanthea simplex and the hydroid Kirchenpaueria pinnata. Within this biotope complex, four biotopes have been identified: AmenCio, LgAsSp, AntAsH and NeoPro.
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 |
|---|---|---|---|
| Corallinaceae | 8 | Common | 41-60% |
| Ophiothrix fragilis | 8 | Frequent | 61-80% |
| Spirobranchus triqueter | 8 | Frequent | 61-80% |
| Echinus esculentus | 7 | Occasional | 61-80% |
| Ascidia mentula | 5 | Occasional | 61-80% |
| Asterias rubens | 5 | Occasional | 61-80% |
| Ciona intestinalis | 5 | Occasional | 61-80% |
| Ophiocomina nigra | 4 | Frequent | 41-60% |
| Munida rugosa | 3 | Occasional | 41-60% |
| Novocrania anomala | 3 | Frequent | 21-40% |
| Pagurus bernhardus | 3 | Occasional | 41-60% |
| Alcyonium digitatum | 2 | Occasional | 21-40% |
| Caryophyllia smithii | 2 | Occasional | 41-60% |
| Corella parallelogramma | 2 | Occasional | 41-60% |
| Crossaster papposus | 2 | Occasional | 41-60% |
| Ophiura albida | 2 | Occasional | 21-40% |
| Pododesmus patelliformis | 2 | Occasional | 21-40% |
| Protanthea simplex | 2 | Occasional | 21-40% |
| Antedon bifida | 1 | Occasional | 21-40% |
| Ascidia virginea | 1 | Occasional | 21-40% |
| Clavelina lepadiformis | 1 | Occasional | 21-40% |
| Henricia oculata | 1 | Rare | 21-40% |
| Kirchenpaueria pinnata | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.