Description of biotope or habitat type
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Polydora ciliata and Corophium volutator in variable salinity infralittoral firm mud or clay
Physical habitat description
| Salinity | Variable (18-35 ppt) |
|---|---|
| Wave exposure | Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Weak (>1 kn) |
| Substratum | Hard clay, relict peat, mud with fine sand fraction |
| 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
Variable salinity clay and firm mud characterised by a turf of the polychaete Polydora ciliata along with the amphipod Corophium volutator. Other important taxa include the polychaetes Pygospio elegans, Hediste diversicolor, Streblospio shrubsolii and the oligochaete Tubificoides benedii. P. ciliata also occurs in high densities elsewhere (see CR.MCR.SfR.Pol) and may be a specific feature of the Humber Estuary in these conditions. This biotope occurs only in very firm mud and clay and possibly submerged relict saltmarsh with a high detrital content. It is characterised, and can be separated from other biotopes, by a combination of the sediment characteristics and the very high density of Polydora ciliata. In some areas, such as the Humber estuary, cyclical behaviour with regard to its characteristic taxa has been reported with either P. ciliata or C. volutator increasing in dominance at the expense of the other (Gameson 1982). It is possible that changes in water quality or the sediment regime may be responsible for this.
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 | Typical abundance - (count per m2) | % of core records where taxon was recorded |
|---|---|---|---|---|
| Polydora ciliata | 43 | Abundant | 6407 | 81-100% |
| Corophium volutator | 21 | Common | 556 | 61-80% |
| Pygospio elegans | 9 | Frequent | 152 | 61-80% |
| Streblospio shrubsolii | 6 | Common | 642 | 41-60% |
| Hediste diversicolor | 5 | Common | 84 | 61-80% |
| Tubificoides benedii | 4 | Frequent | 616 | 61-80% |
| Eteone longa | 2 | Common | 32 | 41-60% |
| Tharyx | 2 | Common | 877 | 21-40% |
| Tubificoides pseudogaster | 2 | Abundant | 2850 | 21-40% |
| Peringia ulvae | 1 | Common | 332 | 21-40% |
| Gammarus salinus | 1 | Common | 6 | 21-40% |
Similar biotopes or habitat types
SS.SMu.SMuVS.AphTubi
These two biotopes are similar in characteristics but can be distinguished on the relative abundances of the characterising species Polydora ciliata, Corophium volutator and Aphelochaeta marioni.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMu.SMuVS.PolCvol | Polydora ciliata and Corophium volutator in variable salinity infralittoral firm mud or clay |
| 2004 (04.05) | SS.SMu.SMuVS.PolCvol | Polydora ciliata and Corophium volutator in variable salinity infralittoral firm mud or clay |
| 1997 (97.06) | SS.IMU.PolVS | Polydora ciliata in variable salinity infralittoral firm mud or clay |