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Marine Habitat Classification

Description of biotope or habitat type

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   Calocaris macandreae and polychaetes in offshore circalittoral mud and sandy mud

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Very sheltered 
Tidal streams Week
Substratum Mud, Sandy mud
Zone Circalittoral
Depth Band 50-150 m
Other Features

Biotope origin

Derived using data from Day Grab
Faunal group 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.

Distribution of habitat SS.SMu.OMu.CalPol <I> Calocaris macandreae</I>  and polychaetes in offshore circalittoral mud and sandy mud

  • 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.


Sublittoral mud and sandy mud plains characterised by a wide range of infauna including polychaetes, few crustaceans and molluscs. This biotope has been found in the Irish Sea, the Minches, and Western Scotland. The description of this biotope is based on infauna recorded from the above location but could be found in other areas with similar environmental conditions. The characteristic infaunal species include Calocaris macandreae and polychaetes Glycera unicornis, Mediomastus fragilis, Levinsenia gracilis and oligochaete Tubificoides amplivastus. The other characterising taxa include polychaetes Nephtys incisa, Kirkegaardia dorsbranchialis (previously Monticellina) and bivalve Nucula sulcata. Echinoidean Brissopsis lyrifera, cumacean Eudorella emarginata, and Nephrops norvegicus are also present in small numbers. This biotope was described using Day grab infaunal data and the characterising species listed will partly reflect the method used to collect data.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) % of core records where taxon was recorded Relative frequency %
Calocaris macandreae 19 1-20% 5.7
Glycera unicornis 15 1-20% 6.2
Levinsenia gracilis 13 21-40% 29.5
Tubificoides amplivasatus 13 1-20% 9.8
Mediomastus fragilis 9 1-20% 7.5
Nucula sulcata 9 1-20% 7.5
Monticellina dorsobranchialis 9 1-20% 18
Nephtys incisa 6 1-20% 2.5
Litocorsa stremma 3 1-20% 2.8
Nemertea 1 1-20% 0.9

Similar biotopes or habitat types

Not applicable or unknown.

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