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Marine Habitat Classification

Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Echinoderms and crustose communities

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Extremely exposed, Very exposed, Exposed, Moderately exposed
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Bedrock, boulders
Zone Circalittoral - lower, Circalittoral - upper
Depth Band 10-20 m, 20-30 m, 30-50 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.

Distribution of habitat CR.MCR.EcCr Echinoderms and crustose communities

  • 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.


This biotope complex occurs on wave-exposed, moderately strong to weakly tide-swept, circalittoral bedrock and boulders. Echinoderms, faunal (Parasmittina trispinosa) and algal crusts (red encrusting algae) dominate this biotope, giving a sparse appearance. Typical echinoderms present are the starfish Asterias rubens, the brittlestar Ophiothrix fragilis and the sea urchin Echinus esculentus. There may be isolated clumps of the hydroids Nemertesia antennina and Abietinaria abietina, Alcyonium digitatum, the anemone Urticina felina and the cup coral Caryophyllia smithii. Other species present may include the polychaete Spirobranchus triqueter and the top shell Calliostoma zizphinum. Five biotopes have been identified within this biotope complex: CarSwi, CarSp, FaAlCr, UrtScr and AdigVT.


No situation data available.

Temporal variation

No temporal variation data available.

Characterising species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Abietinaria abietina Occasional 41-60%
Alcyonium digitatum Frequent 81-100%
Asterias rubens Occasional 61-80%
Calliostoma zizyphinum Occasional 41-60%
Caryophyllia smithii Frequent 41-60%
Corallinaceae Common 61-80%
Echinus esculentus Frequent 81-100%
Nemertesia antennina Occasional 41-60%
Ophiothrix fragilis Frequent 41-60%
Parasmittina trispinosa Frequent 41-60%
Spirobranchus triqueter Frequent 41-60%
Urticina felina Occasional 41-60%

Similar biotopes or habitat types

Not applicable or unknown.

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