Description of biotope or habitat type
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Atrina fragilis and echinoderms on circalittoral mud
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Very exposed, Exposed, Moderately exposed |
| Tidal streams | |
| Substratum | Mud |
| Zone | Circalittoral |
| Depth Band | 100-150 m |
| Other Features |
Biotope origin
| Derived using data from | Video/still |
| Faunal group | Epifauna |
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
Circalittoral mud and mixed sediments characterised by the epifaunal assemblage of fan mussel Atrina fragilis and brittle star Amphiura. The description of this biotope is based on epifauna recorded from Small Isles (northwest Scotland) but could be found in other areas with similar environmental conditions. The fauna was diverse with burrowing crustaceans, echinoderms, sea anemones, ascidians and bryozoans. The characteristic fauna includes anemone Sagaritogeton lacerates, Alcyonidium digitatum, Hydrozoa, serpulid worm Salmacina dysteri and Munida rugosa. The description of this biotope is based on video data so the characterising fauna include only those species with an epifaunal expression. This epifaunal biotope may be associated with infaunal biotopes described for similar environmental conditions.
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | % of core records where taxon was recorded | Relative frequency % |
|---|---|---|---|
| Amphiura | 24 | 1-20% | 20.8 |
| Cylista lacerata | 19 | 1-20% | 12.6 |
| Atrina fragilis | 16 | 1-20% | 11.6 |
| Alcyonium digitatum | 8 | 1-20% | 4.7 |
| Hydrozoa | 7 | 1-20% | 5.2 |
| Salmacina dysteri | 7 | 1-20% | 3.8 |
| Munida rugosa | 4 | 1-20% | 4.7 |
| Caridea | 4 | 1-20% | 2.3 |
| Nephrops norvegicus | 3 | 1-20% | 1.8 |
| Nemertesia antennina | 2 | 1-20% | 1.8 |
| Inachus | 1 | 1-20% | 1.8 |
| Ophiothrix fragilis | 1 | 1-20% | 2.8 |
| Paguridae | 1 | 1-20% | 2.3 |
| Urticina | 1 | 1-20% | 1.3 |
| Adamsia palliata | 1 | 1-20% | 2.3 |
| Pagurus prideaux | 1 | 1-20% | 2.3 |
| Leptometra celtica | 1 | 1-20% | 3.3 |
Similar biotopes or habitat types
Not applicable or unknown.