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Marine Habitat Classification


Description of biotope or habitat type

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   Neocrania anomala and Protanthea simplex on sheltered circalittoral rock


Habitat (physical) description

Salinity Full (30-35 ppt), Variable (18-35 ppt)
Wave exposure Sheltered, Very sheltered, Extremely sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock, boulders
Zone Circalittoral
Depth Band 5-10 m, 10-20 m, 20-30 m, 30-50 m
Other Features Steep slopes

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.

Distribution of habitat CR.LCR.BrAs.NeoPro <I>Neocrania anomala</I> and <I>Protanthea simplex</I> on sheltered circalittoral rock

  • 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 typically occurs in full to variable salinity conditions on very wave-sheltered circalittoral bedrock and boulder slopes subject to negligible tidal streams (this tends to be in the landward, very sheltered basins of fjordic sealochs). This biotope is characterised by often dense populations of the anemone Protanthea simplex, growing on the silty bedrock. The underlying rock surfaces are usually covered by encrusting red algae, the polychaete Pomatoceros triqueter, the brachiopods Neocrania anomala and Terebratulina retusa, the saddle oyster Pododesmus patelliformis and the polychaete Sabella pavonina. Scattered colonies of Alcyonium digitatum and the hydroid Bougainvillia ramosa may occasionally be recorded. A diverse range of ascidians including Ciona intestinalis, Ascidia mentula, Corella parallelogramma, Ascidia virginea, Polycarpa pomaria and Dendrodoa grossularia are also occasionally recorded. Echinoderms such as the common brittlestar Ophiothrix fragilis are frequently reported with their arms protruding from crevices in the rock, whilst the starfish Asterias rubens, Henricia oculata, and the sea urchin Echinus esculentus and Psammechinus miliaris are occasionally found on the boulder/rock surface. The whelk Buccinum undatum is often present but in very low numbers. The squat lobster Munida rugosa may be seen hiding in crevices. The hermit crab Pagurus bernhardus may also be recorded.

Situation

No situation data available.

Temporal variation

Not known.

Characterising Species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Bougainvillia ramosa 2 Occasional 21-40 %
Alcyonium digitatum 1 Occasional 21-40 %
Protanthea simplex 7 Common 61-80 %
Sabella pavonina 4 Occasional 61-80 %
Pomatoceros triqueter 10 Frequent 61-80 %
Pagurus bernhardus 2 Occasional 41-60 %
Munida rugosa 2 Occasional 41-60 %
Buccinum undatum 2 Rare 41-60 %
Pododesmus patelliformis 4 Occasional 41-60 %
Neocrania anomala 10 Frequent 61-80 %
Terebratulina retusa 1 Occasional 21-40 %
Henricia 1 Rare 21-40 %
Asterias rubens 3 Occasional 41-60 %
Ophiothrix fragilis 3 Occasional 41-60 %
Psammechinus miliaris 3 Occasional 41-60 %
Echinus esculentus 2 Rare 41-60 %
Ciona intestinalis 6 Occasional 61-80 %
Corella parallelogramma 4 Occasional 61-80 %
Ascidia mentula 5 Occasional 61-80 %
Ascidia virginea 3 Occasional 41-60 %
Polycarpa pomaria 2 Occasional 41-60 %
Dendrodoa grossularia 2 Common 21-40 %
Corallinaceae 6 Common 41-60 %

Similar biotopes

Not applicable or unknown.

Photos

CR.LCR.BRAS.NeoPro Neocrania anomala and Protanthea simplex on sheltered circalittoral rock, Point N of Tob a Tuath na Ceannamhoire, Loch Seaforth, Lewis. Dale Rostron © JNCC
CR.LCR.BRAS.NeoPro Neocrania anomala and Protanthea simplex on sheltered circalittoral rock, Point N of Tob a Tuath na Ceannamhoire, Loch Seaforth, Lewis. Dale Rostron © JNCC

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