Description of biotope or habitat type
To understand more about what this page is describing, see How to use the classification. See also How to cite.
Polychaete-rich deep Venus community in offshore mixed sediments
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed, Sheltered |
| Tidal streams | Weak (>1 kn) |
| Substratum | Gravelly sand and muddy mixed sediment |
| Zone | Circalittoral |
| Depth Band | 20-30 m, 30-50 m, 50-100 m |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Infauna |
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
In offshore circalittoral slightly muddy mixed sediments, a diverse community particularly rich in polychaetes with a significant venerid bivalve component may be found. Typical species include the polychaetes Glycera lapidum, Aonides paucibranchiata, Laonice bahusiensis, Mediomastus fragilis, Hilbigneris gracilis, Pseudomystides limbata, Protomystides bidentata and syllid species and bivalves such as Timoclea ovata, Glycymeris glycymeris, Spisula elliptica and Goodallia triangularis. Some examples of this biotope may have abundant juvenile Modiolus modiolus. Several echinoderms including Amphipholis squamata, Echinocyamus pusillus are present in many locations. In coarser variations of the biotope, with gravelly sediment and the presence of pebbles or cobbles, the biotope may support encrusting fauna such as hydroids, Sertularia cupressina and Hydrallmania falcata, bryozoans and Spirobranchus triqueter. Mobile crustacea including the long-clawed porcelain crab Pisidia longicornis and amphipod Nototropis vedlomensis can also be highly abundant. This biotope has been recorded in the Irish Sea and English Channel and collectively with SS.SCS.CCS.MedLumVen comprise the 'Deep Venus Community' and the 'Boreal Off-Shore Gravel Association' as defined by other workers (Ford 1923; Jones 1950).
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 % |
|---|---|---|---|
| Laonice bahusiensis | 8 | 1-20% | 1.5 |
| Aonides paucibranchiata | 7 | 1-20% | 2.6 |
| Nemertea | 7 | 1-20% | 1.6 |
| Amphipholis squamata | 6 | 1-20% | 1.8 |
| Notomastus latericeus | 4 | 1-20% | 0.4 |
| Leptochiton asellus | 3 | 1-20% | 2.3 |
| Scalibregma celticum | 3 | 1-20% | 0.3 |
| Glycera lapidum | 3 | 1-20% | 1.2 |
| Echinocyamus pusillus | 3 | 1-20% | 1.7 |
| Hilbigneris gracilis | 3 | 1-20% | 1.1 |
| Sabellaria spinulosa | 2 | 1-20% | 5.5 |
| Galathea intermedia | 2 | 1-20% | 0.5 |
| Ampharete finmarchica | 2 | 1-20% | 0.1 |
| Mediomastus fragilis | 2 | 1-20% | 2.8 |
| Ampelisca spinipes | 2 | 1-20% | 0.5 |
| Spirobranchus triqueter | 1 | 1-20% | 0.6 |
| Lysidice unicornis | 1 | 1-20% | 0.7 |
| Polycirrus | 1 | 1-20% | 0.8 |
| Eusyllinae | 1 | 1-20% | 0.1 |
| Timoclea ovata | 1 | 1-20% | 0.7 |
| Aphelochaeta | 1 | 1-20% | 0.2 |
| Harmothoe | 1 | 1-20% | 0.6 |
| Ampharete lindstroemi | 1 | 1-20% | 1.8 |
| Othomaera othonis | 1 | 1-20% | 0.3 |
| Maldanidae | 1 | 1-20% | 0.2 |
| Eunice dubitata | 1 | 1-20% | 0.1 |
| Glycymeris glycymeris | 1 | 1-20% | 0.8 |
| Lepidonotus squamatus | 1 | 1-20% | 0.3 |
| Dendrodoa grossularia | 1 | 1-20% | 2.6 |
| Phyllodocidae | 1 | 1-20% | 0.1 |
| Psammechinus miliaris | 1 | 1-20% | 0.1 |
| Pholoe inornata | 1 | 1-20% | 0.3 |
| Myrianida | 1 | 1-20% | 0.4 |
| Syllis | 1 | 1-20% | 0.5 |
| Hydroides norvegica | 1 | 1-20% | 0.6 |
| Poecilochaetus serpens | 1 | 1-20% | 0.2 |
| Achelia echinata | 1 | 1-20% | 0.6 |
Similar biotopes or habitat types
Not applicable or unknown.
Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMx.OMx.PoVen | Polychaete-rich deep Venus community in offshore mixed sediments |
| 2004 (04.05) | SS.SMx.OMx.PoVen | Polychaete-rich deep Venus community in offshore mixed sediments |
| 1997 (97.06) | Part of SS.CGS.Ven | Venerid bivalves in circalittoral coarse sand or gravel |