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Marine Habitat Classification


Description of biotope or habitat type

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   Thyasira spp. and Nuculoma tenuis in circalittoral sandy mud


Habitat (physical) description

Salinity Full (30-35 ppt)
Wave exposure Moderately exposed, Sheltered
Tidal streams Very weak (negligible)
Substratum Mud occasionally with scattered shells or gravel
Zone Circalittoral
Depth Band 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.SMu.CSaMu.ThyNten <I>Thyasira</I> spp. and <I>Nuculoma tenuis</I> in circalittoral 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.

Description

Circalittoral cohesive sandy muds with small quantities of gravel, off sheltered or moderately exposed coasts may support populations characterised by Thyasira spp. and in particular Thyasira flexuosa. Other characteristic taxa may include Nuculoma tenuis, Goniada maculate and in some areas Rhodine gracilior. Mysella bidentata, Abra alba, Harpinia antennaria and Amphiura filiformis may be abundant in some examples of this biotope. Whilst moderately diverse, animal abundances are often low and it is possible that the biotope is the result of sedimentary disturbance e.g. from trawling and is possibly an impoverished version of AfilNten. Collectively the biotopes ThyNten, AfilMysAnit, AfilNten and OfusAfil, may form the Amphiura dominated components of the 'off-shore muddy sand association' described by other workers (Jones 1951; Thorson 1957; Mackie 1990) and the infralittoral etage described by Glemarec (1973).

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
Virgularia mirabilis 1 21-40 %
Nemertea 7 61-80 %
Pholoe inornata 1 21-40 %
Glycera rouxii 2 21-40 %
Goniada maculata 5 61-80 %
Nephtys 2 41-60 %
Lumbrineris hibernica 3 21-40 %
Paraonidae 2 21-40 %
Spiophanes bombyx 1 21-40 %
Spiophanes kroyeri 1 21-40 %
Chaetozone setosa 2 41-60 %
Diplocirrus glaucus 2 41-60 %
Rhodine gracilior 4 Common 41-60 %
Scalibregma inflatum 1 Common 21-40 %
Galathowenia oculata 3 21-40 %
Owenia fusiformis 2 Common 21-40 %
Anobothrus gracilis 1 21-40 %
Terebellides stroemi 3 21-40 %
Harpinia antennaria 3 Frequent 41-60 %
Cylichna cylindracea 2 41-60 %
Nuculoma tenuis 4 Frequent 41-60 %
Lucinoma borealis 2 41-60 %
Thyasira 1 Common 1-20 %
Thyasira flexuosa 12 Frequent 61-80 %
Thyasira flexuosa 50 Occasional 81-100 %
Mysella bidentata 3 Frequent 41-60 %
Phaxas pellucidus 1 21-40 %
Abra alba 3 41-60 %
Abra alba 25 81-100 %
Mya arenaria 25 81-100 %
Amphiura filiformis 3 Abundant 41-60 %

Similar biotopes

SS.SMu.CSaMu.AfilNten
The current biotope may be distinguished from AfilNten by the differing abundances of the characterising species Amphiura filiformis and Thyasira flexuosa in the two biotopes.


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