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Marine Habitat Classification

Description of biotope or habitat type

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   Lithophyllum fasciculatum maerl beds on infralittoral mud

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Mud and muddy gravel with shell
Zone Infralittoral
Depth Band 0-5 m
Other Features

Biotope origin

Derived using data from Recording (Phase II)
Faunal group Epifauna

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.SMp.Mrl.Lfas <I>Lithophyllum fasciculatum</I> maerl beds on infralittoral 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.


Shallow, sheltered infralittoral muddy plains with Lithophyllum fasciculatum maerl. This rarely recorded maerl species forms flattened masses or balls several centimetres in diameter (Irvine & Chamberlain 1994). Lfas may be found on mud and muddy gravel mixed with shell. Species of anemone typical of sheltered conditions may be found in association, for example, Anthopleura ballii, Cereus pedunculatus and Cylista undata. Polychaetes such as Myxicola infundibulum and terebellids, also characteristic of sheltered conditions, may be present as may hydroids such as Kirchenpaueria pinnata. Occasional Mimachlamys varia and Thyone fuscus are present in all records of this biotope and red seaweeds such as Plocamium cartilagineum, Calliblepharis jubata and Chylocladia verticillata are often present.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Lithophyllum fasciculatum 18 Common 81-100%
Carcinus maenas 9 Occasional 81-100%
Mimachlamys varia 9 Occasional 81-100%
Thyone fusus 9 Occasional 81-100%
Seraphsidae 8 Frequent 81-100%
Myxicola infundibulum 5 Frequent 61-80%
Anthopleura ballii 3 Occasional 61-80%
Asterias rubens 3 Occasional 61-80%
Cereus pedunculatus 3 Occasional 61-80%
Kirchenpaueria pinnata 3 Occasional 61-80%
Liocarcinus depurator 3 Occasional 61-80%
Pagurus bernhardus 3 Occasional 61-80%
Plocamium cartilagineum 3 Occasional 61-80%
Pomatoschistus pictus 3 Occasional 61-80%
Cylista undata 3 Occasional 61-80%
Calliblepharis jubata 2 61-80%
Cancer pagurus 2 Rare 61-80%
Chylocladia verticillata 2 61-80%
Hydractinia echinata 2 61-80%
Lomentaria clavellosa 2 61-80%
Macropodia rostrata 2 Rare 61-80%
Ophiothrix fragilis 2 61-80%
Spyridia filamentosa 2 61-80%
Suberites ficus 2 Rare 61-80%

Similar biotopes or habitat types

Similar habitat with different dominant maerl species.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2004 (04.05) SS.SMp.Mrl.Lfas Lithophyllum fasciculatum maerl beds on infralittoral mud
1997 (97.06) SS.IMX.MrlMx.Lfas Lithophyllum fasciculatum maerl beds with Chlamys varia on infralittoral sandy mud or mud

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