Description of biotope or habitat type
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Gracilechinus acutus norvegicus assemblage on Atlantic lower bathyal sand
Physical habitat description
| Salinity | Full (30-35 ppt) |
|---|---|
| Wave exposure | |
| Tidal streams | |
| Substratum | Sand |
| Zone | Atlantic lower bathyal |
| Depth Band | Biotope depth range 1300 - 2100 m (based on zone); assemblage recorded from 150 - 1400 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 aggregations of Gracilechinus acutus norvegicus (previously Echinus acutus norvegicus) on sand substrate. The same epifaunal assemblage is also found on mud and sand in the upper and mid bathyal but associated infauna are likely to differ. Gage (1986) reports this assemblage from 700-1400m on pelagic ooze and suggests it is present in a ribbon-like distribution around the continental margin of Europe down to about 1400m. Le Danois also describes this assemblage from 150m-500+ but emphasises that shallower than 500m Spatangus raschi dominates and below Gracilechinus acutus norvegicus dominates. Characterising species listed refer to all Gracilechinus acutus norvegicus 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 acutus | |
| Spatangus raschi | |
| Nematocarcinus ensifer | |
| Pontophilus norvegicus | |
| Geryon trispinosus | |
| Nephropsis atlantica | |
| Ophiocten gracilis | |
| Calveriosoma hystrix | |
| Bathyplotes natans | |
| Laetmogone violacea | |
| Benthogone rosea |
Similar biotopes or habitat types
M.AtLB.Mu.UrcCom.GraAcu
The same epifaunal assemblage on mud. Associated infauna are likely to differ.
M.AtMB.Mu.UrcCom.GraAcu
The same epifaunal assemblage in the mid bathyal on mud. Associated infauna are likely to differ.
M.AtMB.Sa.UrcCom.GraAcu
The same epifaunal assemblage in the mid bathyal on sand. Associated infauna are likely to differ.
M.AtUB.Sa.UrcCom.GraAcu
The same epifaunal assemblage in the upper bathyal on sand. Associated infauna are likely to differ.
M.AtLB.Mu.UrcCom.GraAle
Assemblage occurs on mud. The dominant urchin species is Gracilechinus alexandri.