Description of biotope or habitat type
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Phymatolithon calcareum maerl beds with Neopentadactyla mixta and other echinoderms in deeper infralittoral clean gravel or coarse sand
Physical habitat description
Salinity | Full (30-35 ppt) |
---|---|
Wave exposure | Exposed, Moderately exposed, Sheltered |
Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
Substratum | Maerl gravel; coarse sand |
Zone | Circalittoral - upper, Infralittoral - lower |
Depth Band | 5-10 m, 10-20 m, 20-30 m |
Other Features |
Biotope origin
Derived using data from | Various |
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
Lower infralittoral maerl beds characterised by Phymatolithon calcareum in gravels and sand with a variety of associated echinoderms. The echinoderm Neopentadactyla mixta is frequently observed in this biotope. Other echinoderms such as Echinus esculentus, Ophiura albida and rarely Luidia ciliaris may also be present. Red seaweed such as Plocamium cartilagineum may be present but at a much lower abundance than in SS.SMp.Mrl.Pcal.R and with fewer species present. Other, more ubiquitous echinoderms such as Asterias rubens may also be found in low numbers throughout SS.SMp.Mrl.Pcal biotopes.
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
---|---|---|---|
Phymatolithon calcareum | 20 | Common | 61-80% |
Pagurus bernhardus | 10 | Occasional | 61-80% |
Asterias rubens | 8 | Occasional | 81-100% |
Neopentadactyla mixta | 4 | Frequent | 41-60% |
Echinus esculentus | 4 | Occasional | 41-60% |
Cerianthus lloydii | 3 | Occasional | 41-60% |
Saccharina latissima | 3 | Occasional | 41-60% |
Lanice conchilega | 3 | Occasional | 41-60% |
Liocarcinus depurator | 3 | Occasional | 41-60% |
Pecten maximus | 3 | Occasional | 41-60% |
Chaetopterus variopedatus | 2 | Occasional | 41-60% |
Ensis | 2 | Frequent | 21-40% |
Gibbula magus | 2 | Occasional | 41-60% |
Plocamium cartilagineum | 2 | Occasional | 41-60% |
Spirobranchus triqueter | 2 | Occasional | 41-60% |
Desmarestia viridis | 1 | Occasional | 21-40% |
Luidia ciliaris | 1 | Rare | 21-40% |
Ophiura albida | 1 | Occasional | 21-40% |
Tectura virginea | 1 | Occasional | 21-40% |
Pomatoschistus | 1 | Occasional | 21-40% |
Similar biotopes or habitat types
SS.SMp.Mrl.Pcal.R
SS.SMp.Mrl.Pcal.R occurs shallower than SS.SMp.Mrl.Pcal.Nmix with a greater abundance and diversity of red seaweeds.Classification history of this biotope or habitat type
Classification version | Code | Habitat name |
---|---|---|
2004 (04.05) | SS.SMp.Mrl.Pcal.Nmix | Phymatolithon calcareum maerl beds with Neopentadactyla mixta and other echinoderms in deeper infralittoral clean gravel or coarse sand |
1997 (97.06) | SS.IGS.Mrl.Phy.HEc | Phymatolithon calcareum maerl beds with hydroids and echinoderms in deeper infralittoral clean gravel or coarse sand |