Description of biotope or habitat type
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Aphelochaeta spp. and Polydora spp. in variable salinity infralittoral mixed sediment
Physical habitat description
| Salinity | Reduced (18-30ppt), Variable (18-35 ppt), Low (<18ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn) |
| Substratum | Sandy gravelly muddy mixed sediment |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 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 sheltered muddy mixed sediments in estuaries or marine inlets with variable or reduced/low salinity communities characterised by Aphelochaeta marioni and Polydora ciliata may be present. Other important taxa may include the polychaetes Nephtys hombergii, Chaetozone zetlandica and Melinna palmata, tubificid oligochaetes and bivalves such as Abra nitida. Conspicuous epifauna may include members of the bivalve family Cardiidae (cockles) and the slipper limpet Crepidula fornicata. This biotope is often found in polyhaline waters.
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 |
|---|---|---|---|
| Cardiidae | 50 | 41-60% | |
| Aphelochaeta marioni | 33 | Common | 81-100% |
| Crepidula fornicata | 27 | 41-60% | |
| Cirripedia | 14 | Common | 21-40% |
| Polydora ciliata | 10 | Abundant | 61-80% |
| Nephtys hombergii | 8 | Common | 61-80% |
| Chaetozone zetlandica | 5 | Common | 41-60% |
| Polychaeta | 4 | 1-20% | |
| Melinna palmata | 4 | Common | 21-40% |
| Abra nitida | 3 | Common | 41-60% |
| Carcinus maenas | 3 | 1-20% | |
| Tubificoides | 3 | Frequent | 41-60% |
| Eteone longa | 2 | Frequent | 41-60% |
| Harmothoe | 2 | Common | 41-60% |
| Mediomastus fragilis | 2 | 41-60% | |
| Streblospio shrubsolii | 2 | 21-40% | |
| Tubifex | 2 | Frequent | 21-40% |
| Cerastoderma edule | 1 | 41-60% | |
| Ampharete | 1 | Common | 21-40% |
| Capitella capitata | 1 | Occasional | 41-60% |
| Hediste diversicolor | 1 | 41-60% | |
| Lanice conchilega | 1 | Frequent | 21-40% |
| Pygospio elegans | 1 | Frequent | 21-40% |
| Scoloplos armiger | 1 | 21-40% |
Similar biotopes or habitat types
SS.SMu.SMuVS.AphTubi
In areas of mixed sediment, where A. marioni occurs in high numbers, it may be difficult to separate SS.SMu.SMuVS.AphTubi from SS.SMx.SMxVS.AphPol, requiring classification on sediment characteristics and associated species in addition to the abundance of A. marioni.
SS.SMu.SMuVS.PolCvol
SS.SMu.SMuVS.PolCvol is similar to SS.SMx.SMxVS.AphPol but occurs in muddier estuarine conditions.
SS.SMx.SMxVS.CreMed
SS.SMx.SMxVS.CreMed may be distinguished from SS.SMx.SMxVS.AphPol by the abundance of C. fornicata and its sediment characteristics. SS.SMx.SMxVS.AphPol may also be found in reduced salinity conditions.
SS.SMu.ISaMu.MelMagThy
As salinity increases SS.SMx.SMxVS.AphPol may grade into SS.SMu.ISaMu.MelMagThy with those species characteristic of the latter increasing in abundance.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMx.SMxVS.AphPol | Aphelochaeta spp. and Polydora spp. in variable salinity infralittoral mixed sediment |
| 2004 (04.05) | SS.SMx.SMxVS.AphPol | Aphelochaeta spp. and Polydora spp. in variable salinity infralittoral mixed sediment |
| 1997 (97.06) | SS.IMX.EstMx.PolMtru | Polydora ciliata, Mya truncata and solitary ascidians in variable salinity infralittoral mixed sediment |