Description of biotope or habitat type
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Hiatella-bored vertical sublittoral limestone rock
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Bedrock |
| Zone | Circalittoral |
| Depth Band | 0-5 m, 5-10 m, 10-20 m |
| Other Features | Vertical limestone or chalk. |
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
Moderately exposed vertical and overhanging soft rock (typically chalk), subject to moderately strong to weak tidal streams, bored by the rock-boring mollusc Hiatella arctica. As with other biotopes in the soft rock complex, it is found in areas of high turbidity, where there is poor light penetration. There may be isolated clumps of the hydroid Nemertesia antennina and a sparse bryozoan turf formed by various crisiids, Crisularia plumosa and Bugula flabellate (often being grazed on by the nudibranch Antiopella cristata), Alcyonidium diaphanum, Flustra foliacea and Cellapora pumicosa. A patchy 'carpet' of the brittlestar Ophiothrix fragilis is often recorded along with other echinoderms such as Asterias rubens and Henricia sanguinolenta. Other species present include the colonial ascidians Polyclinum aurantium, Botrylloides leachii, Clavelina lepadiformis, Aplidium punctatum and Botryllus schlosseri, dead mans fingers Alcyonium digitatum and the crab Cancer pagurus. Sponges present include the boring sponge Cliona celata, Halichondria panicea, Myxilla incrustans, Leucosolenia botryoidesand Dysidea fragilis. Occasionally, the foliose red seaweed Delessaria sanguinea may be recorded.
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 |
|---|---|---|---|
| Ophiothrix fragilis | 10 | Common | 61-80% |
| Asterias rubens | 9 | Frequent | 61-80% |
| Hiatella arctica | 7 | Common | 61-80% |
| Crisiidae | 5 | Common | 41-60% |
| Polyclinum aurantium | 5 | Frequent | 61-80% |
| Botrylloides leachii | 4 | Frequent | 41-60% |
| Crisularia plumosa | 4 | Frequent | 41-60% |
| Alcyonidium diaphanum | 3 | Frequent | 41-60% |
| Alcyonium digitatum | 3 | Common | 41-60% |
| Aplidium punctum | 2 | Common | 21-40% |
| Botryllus schlosseri | 2 | Occasional | 21-40% |
| Bugulina flabellata | 2 | Frequent | 41-60% |
| Cancer pagurus | 2 | Occasional | 41-60% |
| Clavelina lepadiformis | 2 | Frequent | 41-60% |
| Cliona celata | 2 | Frequent | 21-40% |
| Delesseria sanguinea | 2 | Frequent | 21-40% |
| Flustra foliacea | 2 | Common | 21-40% |
| Halichondria panicea | 2 | Frequent | 41-60% |
| Henricia sanguinolenta | 2 | Occasional | 21-40% |
| Antiopella cristata | 2 | Frequent | 21-40% |
| Leucosolenia botryoides | 2 | Frequent | 41-60% |
| Cellepora pumicosa | 1 | Occasional | 41-60% |
| Dysidea fragilis | 1 | 21-40% | |
| Myxilla incrustans | 1 | Occasional | 21-40% |
| Nemertesia antennina | 1 | Frequent | 21-40% |
| Sabellaria spinulosa | 1 | Frequent | 21-40% |
Similar biotopes or habitat types