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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.

   Limaria hians beds in tide-swept sublittoral muddy mixed sediment

Physical habitat description

Salinity Full (30-35 ppt), Variable (18-35 ppt)
Wave exposure Sheltered, Very sheltered, Extremely sheltered
Tidal streams Strong (3-6 kn), Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Mixed muddy sandy gravel
Zone Infralittoral - lower, Circalittoral
Depth Band 5-10 m, 10-20 m, 20-30 m
Other Features Consolidated bed formed from byssus-bound debris

Biotope origin

Derived using data from Various
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.SMx.IMx.Lim <I>Limaria hians</I> beds in tide-swept sublittoral muddy mixed sediment

  • 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.


Mixed muddy gravel and sand often in tide-swept narrows in the entrances or sills of sea lochs with beds or 'nests' of Limaria hians. The Limaria form woven 'nests' or galleries from byssus and fragments of seaweeds so that the animals themselves cannot be seen from above the seabed. Modiolus modiolus sometimes occur at the same sites lying over the top of the Limaria bed. Other fauna associated with this biotope include echinoderms (Ophiothrix fragilis, Ophiocomina nigra and Asterias rubens), Buccinum undatum, mobile crustaceans (e.g. Pagurus bernhardus), Alcyonium digitatum and hydroids such as Plumularia setacea, Kirchenpaueria pinnata and Nemertesia spp. Sometimes red seaweeds such as Phycodrys rubens occur if the beds are in shallow enough water.


No situation data available.

Temporal variation

No temporal data available.

Characterising species

Taxon Typical abundance - SACFOR scale % of core records where taxon was recorded
Kirchenpaueria pinnata Occasional 41-60%
Nemertesia antennina Frequent 21-40%
Nemertesia ramosa Frequent 21-40%
Limaria hians Abundant 81-100%
Ophiothrix fragilis Common 81-100%
Buccinum undatum Occasional 61-80%
Alcyonium digitatum Rare 61-80%
Ophiocomina nigra Common 41-60%
Asterias rubens Occasional 61-80%
Pagurus bernhardus Occasional 41-60%
Modiolus modiolus Occasional 41-60%
Cancer pagurus Occasional 41-60%
Hyas araneus Occasional 41-60%
Pecten maximus Rare 41-60%
Psammechinus miliaris 21-40%
Echinus esculentus Occasional 41-60%
Aequipecten opercularis Occasional 21-40%
Munida rugosa Occasional 21-40%
Necora puber 21-40%
Spirobranchus triqueter Occasional 21-40%

Similar biotopes or habitat types

SS.SMx.IMx.Lim is found in muddier, more sheltered conditions in similar depths.

SS.SMx.IMx.Lim is sometimes found amongst maerl gravels but is deeper than SS.SMp.Mrl.Lgla.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SMx.IMx.Lim Limaria hians beds in tide-swept sublittoral muddy mixed sediment
2004 (04.05) SS.SMx.IMx.Lim Limaria hians beds in tide-swept sublittoral muddy mixed sediment
1997 (97.06) SS.IMX.FaMx.Lim Limaria hians beds in tide-swept sublittoral muddy mixed sediment

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