Description of biotope or habitat type
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Gracilechinus alexandri, Psilaster and Plinthaster assemblage on Atlantic upper abyssal mud
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | |
| Tidal streams | |
| Substratum | Mud - pelagic ooze and terbidite |
| Zone | Atlantic upper Abyssal |
| Depth Band | Biotope depth range 2100 - 3100 m; assemblage recorded from 1400 - 2500 m |
| Other Features |
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
This biotope consists of urchin Gracilechinus alexandri with seastars on mud substrate. Gage (1986) describes an assemblage from the continental slope west of the Hebrides (Rockall Trough) between 1400 and 2500m on pelagic ooze and terbidite dominated by echinoderms. The same epifaunal assemblage is also found in the lower bathyal but associated infauna are likely to differ. Characterising species listed refer to all Gracilechinus alexandri, Psilaster and Plinthaster assemblages not just those found associated with the zone and substrate specified in this biotope.
Situation
No situation data available.
Temporal variation
No temporal variation data available.
Characterising species
| Taxon | % of core records where taxon was recorded |
|---|---|
| Gracilechinus alexandri | |
| Persephonaster patagiatus | |
| Plinthaster dentatus | |
| Munidopsis curvirostra | |
| Stereomastis sculpta | |
| Neolithodes grimaldii | |
| Colus jeffreysianus | |
| Troschelia berniciensis |
Similar biotopes or habitat types
M.AtLB.Mu.UrcCom.GraAcu
Assemblage occurs in the lower bathyal. The dominant urchin species is Gracilechinus acutus.
M.AtLB.Sa.UrcCom.GraAcu
Assemblage occurs in the lower bathyal on sand. The dominant urchin species is Gracilechinus acutus.
M.AtMB.Mu.UrcCom.GraAcu
Assemblage occurs in the mid bathyal on mud. The dominant urchin species is Gracilechinus acutus.
M.AtMB.Sa.UrcCom.GraAcu
Assemblage occurs in the mid bathyal on sand. The dominant urchin species is Gracilechinus acutus.
M.AtUB.Sa.UrcCom.GraAcu
Assemblage occurs in the upper bathyal on sand. The dominant urchin species is Gracilechinus acutus.