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Marine Habitat Classification


Description of biotope or habitat type

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   Mysella bidentata and Thyasira spp. in circalittoral muddy mixed sediment


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered
Tidal streams Moderately strong (1-3 kn), Weak (>1 kn)
Substratum Muddy sand and gravel
Zone Circalittoral
Depth Band 10-20 m, 20-30 m, 30-50 m, 50-100 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 SS.SMx.CMx.MysThyMx <I>Mysella bidentata</I> and <I>Thyasira</I> spp. in circalittoral 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.

Description

In moderately exposed or sheltered, circalittoral muddy sands and gravels a community characterised by the bivalves Thyasira spp. (often Thyasira flexuosa), Mysella bidentata and Prionospio fallax may develop. Infaunal polychaetes such as Lumbrineris gracilis, Chaetozone setosa and Scoloplos armiger are also common in this community whilst amphipods such as Ampelisca spp. and the cumacean Eudorella truncatula may also be found in some areas. The brittlestar Amphiura filiformis may also be abundant at some sites. Conspicuous epifauna may include encrusting bryozoans Escharella spp. particularly Escharella immersa and, in shallower waters, maerl (Phymatolithon calcareum), although at very low abundances and not forming maerl beds.

Situation

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
Scypha ciliata 2 21-40 %
Sertularia cupressina 1 21-40 %
Laomedea flexuosa 2 41-60 %
Anthozoa 9 1-20 %
Nemertea 2 Common 61-80 %
Nematoda 3 Frequent 61-80 %
Pholoe inornata 2 Frequent 61-80 %
Goniada maculata 2 Common 61-80 %
Nephtys 1 Common 41-60 %
Nephtys hombergii 2 Common 61-80 %
Lumbrineris gracilis 4 Common 81-100 %
Scoloplos armiger 3 Abundant 81-100 %
Levinsenia gracilis 1 Common 41-60 %
Prionospio fallax 8 Abundant 81-100 %
Spiophanes bombyx 2 Frequent 61-80 %
Chaetozone setosa 4 Common 81-100 %
Mediomastus fragilis 2 Common 41-60 %
Scalibregma inflatum 2 Common 61-80 %
Galathowenia oculata 1 Frequent 41-60 %
Owenia fusiformis 2 Common 61-80 %
Terebellides stroemi 2 Abundant 61-80 %
Ampelisca tenuicornis 2 Frequent 61-80 %
Eudorella truncatula 1 Abundant 41-60 %
Thyasira flexuosa 7 Common 81-100 %
Mysella bidentata 5 Frequent 81-100 %
Phaxas pellucidus 1 Common 41-60 %
Abra alba 2 Common 41-60 %
Chamelea gallina 2 Common 61-80 %
Crisidia cornuta 3 21-40 %
Crisia 6 41-60 %
Tubulipora 4 21-40 %
Alcyonidium diaphanum 2 21-40 %
Aetea truncata 1 21-40 %
Electra pilosa 4 21-40 %
Cribrilina punctata 6 41-60 %
Escharoides coccinea 2 21-40 %
Escharella immersa 15 41-60 %
Escharella ventricosa 2 21-40 %
Schizomavella auriculata 2 21-40 %
Microporella ciliata 4 21-40 %
Fenestrulina malusii 6 41-60 %
Cellepora pumicosa 2 21-40 %
Phoronis 2 Common 41-60 %
Amphiura filiformis 1 Abundant 41-60 %
Hildenbrandia rubra 5 21-40 %
Corallinaceae 9 21-40 %
Phymatolithon calcareum 13 41-60 %

Similar biotopes

SS.SMu.CSaMu.AfilMysAnit
The current biotope is closely related to the muddier, less heterogeneous AfilMysAnit

SS.SMu.OMu.ForThy
MysThyMx may be a shallower, less heterogeneous variant of the offshore ForThy biotope

SS.SMu.OMu.PjefThyAfil
MysThyMx may be a shallower, less heterogeneous variant of the offshore PjefThyAfil biotope


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