Description of biotope or habitat type
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Nephtys cirrosa and Bathyporeia spp. in infralittoral sand
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | Exposed, Moderately exposed |
| Tidal streams | Weak (>1 kn), Very weak (negligible) |
| Substratum | Medium to very fine sand |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 m |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna/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
Well-sorted medium and fine sands characterised by Nephtys cirrosa and Bathyporeia spp. (and sometimes Pontocrates spp.) which occur in the shallow sublittoral to at least 30 m depth. This biotope occurs in sediments subject to physical disturbance, as a result of wave action (and occasionally strong tidal streams in outer estuarine variants of the biotope). The magelonid polychaete Magelona mirabilis may be frequent in this biotope in more sheltered, less tideswept areas whilst in coarser sediments the opportunistic polychaete Chaetozone setosa may be commonly found. The faunal diversity of this biotope is considerably reduced compared to less disturbed biotopes (such as SS.SSa.IMuSa.FfabMag) and for the most part consists of the more actively-swimming amphipods. Sand eels Ammodytes sp. may occasionally be observed in association with this biotope (and others) and spionid polychaetes such as Spio filicornis and S. martinensis may also be present. Occasional Lanice conchilega may be visible at the sediment surface. Variants of the biotope in coarser sediment may have more variable fauna, with the absence of Nephtys, and presence of bryozoans, such as Crisia, however retain examples of Bathyporeia spp. and Magelona spp.
Situation
No situation data available.
Temporal variation
Stochastic recruitment events in the Nephtys cirrosa populations may be very important to the population size of other polychaetes present and may therefore create a degree of variation in community composition (Bamber 1994).
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | % of core records where taxon was recorded | Relative frequency % |
|---|---|---|---|
| Nephtys cirrosa | 24 | 1-20% | 3.8 |
| Bathyporeia elegans | 13 | 1-20% | 13.9 |
| Magelona mirabilis | 11 | 1-20% | 3.1 |
| Scoloplos | 6 | 1-20% | 6.4 |
| Magelona filiformis | 5 | 1-20% | 4.7 |
| Bathyporeia pelagica | 4 | 1-20% | 4.9 |
| Nemertea | 4 | 1-20% | 2.5 |
| Spiophanes bombyx | 4 | 1-20% | 2.1 |
| Amphiura filiformis | 2 | 1-20% | 4.7 |
| Abra alba | 2 | 1-20% | 2.7 |
| Nototropis falcatus | 2 | 1-20% | 1.3 |
| Perioculodes longimanus | 2 | 1-20% | 1.2 |
| Crisia | 2 | 1-20% | 0.3 |
| Spio martinensis | 1 | 1-20% | 3.1 |
| Abra prismatica | 1 | 1-20% | 1.5 |
| Aricidea | 1 | 1-20% | 1.3 |
| Pontocrates altamarinus | 1 | 1-20% | 0.9 |
| Synchelidium maculatum | 1 | 1-20% | 0.8 |
| Eteone longa | 1 | 1-20% | 0.8 |
| Magelona johnstoni | 1 | 1-20% | 0.7 |
| Chaetozone setosa | 1 | 1-20% | 0.7 |
| Ennucula tenuis | 1 | 1-20% | 0.6 |
| Scolelepis | 1 | 1-20% | 0.5 |
| Echinocardium cordatum | 1 | 1-20% | 0.4 |
| Galathowenia oculata | 1 | 1-20% | 0.3 |
| Lagotia viridis | 1 | 1-20% | 0.2 |
Similar biotopes or habitat types
SS.SSa.SSaVS.NcirAm
The current biotope is very similar to SS.SSa.SSaVS.NcirAm, which occurs in reduced/variable salinities with additional reduced salinity fauna.
LS.LSa.MoSa.AmSco.Pon
LS.LSa.MoSa.AmSco.Pon is closely allied to SS.SSa.IFiSa.NcirBat but occurs in the intertidal zone.
LS.LSa.FiSa.Po
LS.LSa.FiSa.Po is closely allied to SS.SSa.IFiSa.NcirBat but occurs in the intertidal zone.
SS.SSa.IFiSa.IMoSa
As sediment disturbance increases SS.SSa.IFiSa.NcirBat may grade into LS.LSa.MoSa with only the most robust species able to tolerate the mobile sand environment.
SS.SSa.IMuSa.FfabMag
As sediment disturbance decreases and the finer silt fraction can begin to sediment out of the water column SS.SSa.IFiSa.NcirBat may grade into the muddy sand biotope SS.SSa.IMuSa.FfabMag.Classification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SSa.IFiSa.NcirBat | Nepthys cirrosa and Bathyporeia spp. in infralittoral sand |
| 2004 (04.05) | SS.SSa.IFiSa.NcirBat | Nepthys cirrosa and Bathyporeia spp. in infralittoral sand |
| 1997 (97.06) | SS.IGS.FaS.NcirBat | Nepthys cirrosa and Bathyporeia spp. in infralittoral sand |