Description of biotope or habitat type
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Deep sponge communities (circalittoral)
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Extremely exposed, Very exposed, Exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock |
| Zone | Circalittoral - lower, Circalittoral - upper |
| Depth Band | 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 typically occurs on deep (commonly below 30m depth), wave-exposed circalittoral rock subject to negligible tidal streams. The sponge component of this biotope is the most striking feature, with similar species to the bryozoan and erect sponge biotope complex (BrErSp) although in this case, the sponges Phakellia ventilabrum, Axinella infundibuliformis, Axinella dissimilis and Stelligera stuposa dominate. Other sponge species frequently found on exposed rocky coasts are also present in low to moderate abundance. These include Cliona celata, Polymastia boletiformis, Haliclona viscosa, Pachymatisma johnstonia, Dysidea fragilis, Suberites carnosus, Stelligera montagui, Hemimycale columella and Tethya aurantium. The cup coral Caryophyllia smithii and the anemone Corynactis virdis may be locally abundant in some areas, along with the holothurian Holothuria (Panningothuria) forskali. The soft corals Alcyonium digitatum and Alcyonium glomeratum are frequently observed. The bryozoans Pentapora foliacea and Porella compressa are also more frequently found in this deep-water biotope complex. Bryozoan crusts such as Parasmittina trispinosa are also occasionally recorded. Isolated clumps of large hydroids such as Nemertesia antennina, Nemertesia ramosa and Sertularella gayi may be seen on the tops of boulders and rocky outcrops. Large echinoderms such as Echinus esculentus, Luidia ciliaris, Marthasterias glacialis, Strichastrella rosea, Henricia oculata and Aslia lefevrei may also be present. The sea fan Eunicella verucosa may be locally common but to a lesser extent than in ByErSp.Eun. The top shell Calliostoma zizyphinum is often recorded as present.
Situation
No situation data available.
Temporal variation
Not Known
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Caryophyllia smithii | 6 | Frequent | 81-100% |
| Axinella infundibuliformis | 4 | Frequent | 81-100% |
| Cliona celata | 4 | Frequent | 81-100% |
| Holothuria (Panningothuria) forskali | 4 | Frequent | 81-100% |
| Porella compressa | 4 | Frequent | 81-100% |
| Alcyonium digitatum | 3 | Frequent | 81-100% |
| Calliostoma zizyphinum | 3 | Occasional | 81-100% |
| Dysidea fragilis | 3 | Occasional | 81-100% |
| Haliclona viscosa | 3 | Frequent | 61-80% |
| Henricia oculata | 3 | Occasional | 81-100% |
| Pachymatisma johnstonia | 3 | Occasional | 81-100% |
| Polymastia boletiformis | 3 | Frequent | 81-100% |
| Stelligera stuposa | 3 | Frequent | 81-100% |
| Echinus esculentus | 3 | Occasional | 81-100% |
| Axinella dissimilis | 2 | Occasional | 81-100% |
| Corynactis viridis | 2 | Frequent | 41-60% |
| Luidia ciliaris | 2 | Occasional | 61-80% |
| Marthasterias glacialis | 2 | Occasional | 61-80% |
| Nemertesia antennina | 2 | Occasional | 61-80% |
| Parasmittina trispinosa | 2 | Frequent | 41-60% |
| Pentapora foliacea | 2 | Frequent | 61-80% |
| Phakellia ventilabrum | 2 | Frequent | 61-80% |
| Sertularella gayi | 2 | Occasional | 61-80% |
| Stelligera montagui | 2 | Occasional | 61-80% |
| Suberites carnosus | 2 | Occasional | 61-80% |
| Alcyonium glomeratum | 2 | Frequent | 81-100% |
| Eunicella verrucosa | 1 | Occasional | 41-60% |
| Aslia lefevrei | 1 | Occasional | 41-60% |
| Hemimycale columella | 1 | Occasional | 61-80% |
| Nemertesia ramosa | 1 | Occasional | 61-80% |
| Stichastrella rosea | 1 | Occasional | 41-60% |
| Tethya aurantium | 1 | Occasional | 61-80% |
Similar biotopes or habitat types
Not applicable or unknown.