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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.

   Burrowing megafauna Maxmuelleria lankesteri in circalittoral mud

Physical habitat 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 Mud
Zone Circalittoral
Depth Band 10-20 m, 20-30 m, 30-50 m, 50-100 m
Other Features

Biotope origin

Derived using data from Various
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.CFiMu.MegMax Burrowing megafauna <I>Maxmuelleria lankesteri</I> in circalittoral 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.


In circalittoral stable mud distinctive populations of megafauna may be found with a range of component fauna. This biotope may include the decapod crustaceans Nephrops norvegicus, Munida rugosa, Calocaris macandreae and Callianassa subterranea, the seapens Pennatula phosphorea and Virgularia mirabilis (although in reduced numbers than in SS.SMu.CFiMu.SpnMeg) and the echiuran Maxmuelleria lankesteri sometimes present in large mounds. Whilst this biotope is primarily identified from epifauna, the infaunal species present may include Nephtys hystricis, Chaetozone setosa, Amphiura chiajei and Abra alba. This biotope is closely related to the biotope SS.SMu.CFiMu.SpnMeg and may have infaunal communities similar to the biotopes SS.SMu.CSaMu.AfilKurAnit or SS.SMu.CSaMu.ThyEten, depending on environmental factors and/or the sampling gear used to describe the record.


In some geographic locations (e.g., southern England), seapens are absent from this biotope.

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 %
Nephrops norvegicus 10 1-20% 8.4
Munida rugosa 7 1-20% 5.4
Hydrozoa 6 1-20% 5.2
Actiniaria 6 1-20% 4.9
Bryozoa 6 1-20% 5.2
Decapoda 6 1-20% 5.2
Sertulariidae 6 1-20% 4.9
Ceriantharia 6 1-20% 4.9
Porifera 6 1-20% 4.9
Ascidiacea 6 1-20% 4.9
Galatheidae 6 1-20% 4.9
Nemertesia 5 1-20% 5
Nemertesia ramosa 5 1-20% 4.9
Nemertesia antennina 5 1-20% 4.9
Anthozoa 5 1-20% 4.7
Halecium 5 1-20% 4.7
Ophiuroidea 5 1-20% 4.7

Similar biotopes or habitat types

SS.SMu.CFiMu.MegMax is found in similar habitats but has reduced numbers of seapens and a wider range of megafauna. It is unclear from the data examined which environmental factors separate these two biotopes although SS.SMu.CFiMu.MegMax often occurs in slightly deeper water than SS.SMu.CFiMu.SpnMeg.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SMu.CFiMu.MegMax Burrowing megafauna Maxmuelleria lankesteri in circalittoral mud
2004 (04.05) SS.SMu.CFiMu.MegMax Burrowing megafauna Maxmuelleria lankesteri in circalittoral mud

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