Description of biotope or habitat type
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Tubularia indivisa on tide-swept circalittoral rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Extremely exposed, Very exposed, Exposed |
| Tidal streams | Very strong (>6 kn), Strong (3-6 kn) |
| Substratum | Bedrock, boulder |
| Zone | Circalittoral - lower, Circalittoral - upper |
| Depth Band | 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 is typically found on the vertical and upper faces of strongly tide-swept, wave-exposed circalittoral bedrock and boulders. It is characterised by a dense carpet of the robust hydroid Tubularia indivisa. The barnacle Balanus crenatus, where present, is recorded as common. The accompanying species in the community are determined by tidal stream strength. On the more sheltered sides of headlands, where tidal streams are accelerated, sponges such as Pachymatisma johnstonia, Amphilectus fucorum, Myxilla incrustans and Halichondria panicea proliferate forming the CTub.CuSp sub-biotope. There may also be a scattered bryozoan turf, formed by criisid bryozoans. However, where tidal streams are slightly reduced, but on more wave-exposed coasts, anthozoans such as Alcyonium digitatum become more prominent forming the CTub.Adig biotope. Other species recorded in this biotope include the anemones Cylista elegans, Actinothoe sphyrodeta, Corynactis virdis and Urticina felina. There may be scattered clumps of hydroids such as Sertularia argentea and Nemertesia antennina. Where `relative shelter' is afforded by the topography of the seabed, the bryozoans Flustra foliacea, Alcyonidium diaphanum and the crab Cancer pagurus may be found. More ubiqutous species such as Asterias rubens and Calliostoma zizyphinum may also be present.
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 |
|---|---|---|---|
| Tubularia indivisa | 24 | Abundant | 81-100% |
| Alcyonium digitatum | 11 | Frequent | 81-100% |
| Cylista elegans | 7 | Common | 61-80% |
| Balanus crenatus | 6 | Common | 41-60% |
| Actinothoe sphyrodeta | 4 | Common | 41-60% |
| Amphilectus fucorum | 4 | Frequent | 41-60% |
| Pachymatisma johnstonia | 4 | Occasional | 61-80% |
| Corynactis viridis | 3 | Frequent | 41-60% |
| Alcyonidium diaphanum | 2 | Frequent | 21-40% |
| Asterias rubens | 2 | Occasional | 21-40% |
| Halichondria panicea | 2 | Frequent | 21-40% |
| Myxilla incrustans | 2 | Frequent | 41-60% |
| Nemertesia antennina | 2 | Frequent | 21-40% |
| Urticina felina | 2 | Frequent | 41-60% |
| Porifera | 1 | Frequent | 21-40% |
| Calliostoma zizyphinum | 1 | Occasional | 21-40% |
| Cancer pagurus | 1 | Rare | 41-60% |
| Crisiidae | 1 | Common | 21-40% |
| Flustra foliacea | 1 | Frequent | 21-40% |
| Sertularia argentea | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
Not applicable or unknown.
