JNCC is a statutory adviser to UK Government and devolved administrations
  Home  >  Marine  >  Marine Habitats  >  Habitat  >  Biotope classification


SS.SMx.CMx.MysThyMx
Mysella bidentata and Thyasira spp. in circalittoral muddy mixed sediment

Full Hierarchy  >>  SS >>  SS.SMx >>  SS.SMx.CMx >>  SS.SMx.CMx.MysThyMx

Habitat (physical) description

Distribution

 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  Mysella bidentata and Thyasira spp. in circalittoral muddy mixed sediment
Distribution of habitat SS.SMx.CMx.MysThyMx Mysella bidentata and Thyasira spp. in circalittoral muddy mixed sediment, based on records on the UK Marine Recorder database and EUSeaMap. Red dots represent records on which the biotope is based. Blue dots show other certain records, black dots show records tentatively assigned to this biotope. Yellow areas show level 2 and 3 sublittoral and deep-sea habitats prediced by EUSeaMap within UK waters.

Biotope 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.

Similar biotopes

SS.SMu.CSaMu.AfilMysAnitThe current biotope is closely related to the muddier, less heterogeneous AfilMysAnit
SS.SMu.OMu.ForThyMysThyMx may be a shallower, less heterogeneous variant of the offshore ForThy biotope
SS.SMu.OMu.PjefThyAfilMysThyMx may be a shallower, less heterogeneous variant of the offshore PjefThyAfil biotope

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity Abundance (no.2)
Scypha ciliata P 2
Sertularia cupressina P 1
Laomedea flexuosa P 2
Anthozoa 9
Nemertea C 2 31
Nematoda F 3 487
Pholoe inornata F 2 104
Goniada maculata C 2 27
Nephtys C 1 38
Nephtys hombergii C 2 39
Lumbrineris gracilis C 4 156
Scoloplos armiger A 3 92
Levinsenia gracilis C 1 68
Prionospio fallax A 8 499
Spiophanes bombyx F 2 76
Chaetozone setosa C 4 143
Mediomastus fragilis C 2 149
Scalibregma inflatum C 2 65
Galathowenia oculata F 1 75
Owenia fusiformis C 2 29
Terebellides stroemi A 2 32
Ampelisca tenuicornis F 2 113
Eudorella truncatula A 1 38
Thyasira flexuosa C 7 377
Mysella bidentata F 5 245
Phaxas pellucidus C 1 29
Abra alba C 2 194
Chamelea gallina C 2 44
Crisidia cornuta P 3
Crisia P 6
Tubulipora P 4
Alcyonidium diaphanum P 2
Aetea truncata P 1
Electra pilosa P 4
Cribrilina punctata P 6
Escharoides coccinea P 2
Escharella immersa P 15
Escharella ventricosa P 2
Schizomavella auriculata P 2
Microporella ciliata P 4
Fenestrulina malusii P 6
Cellepora pumicosa P 2
Phoronis C 2 151
Amphiura filiformis A 1 88
Hildenbrandia rubra P 5
Corallinaceae P 9
Phymatolithon calcareum P 13

Example photographs of biotope

No characteristic photos currently available. If you are able to provide a photograph of this biotope please contact .


Version 15.03 of the classification adds a deep-sea section to version 04.05; therefore superseding version 04.05, 97.06 and 03.02.

This online classification should be cited as:

JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed]. Available from: jncc.defra.gov.uk/MarineHabitatClassification

Information from the shallower section (up to sublittoral sediment, taken from Version 04.05) be cited as the report accompanying Version 04.05, as follows:

CONNOR, D.W., J.H. ALLEN, N.GOLDING, K.L.HOWELL, L.M. LIEBERKNECHT, K.O. NORTHEN AND J.B. REKER (2004) The Marine Habitat Classification for Britain and Ireland Version 04.05. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISBN 1 861 07561 8


Information from the deep-sea section (added in March 2015) should be cited as the report accompanying the deep-sea section, as follows:

PARRY, M.E.V., K.L. HOWELL, B.E. NARAYANASWAMY, B.J. BETT, D.O.B. JONES, D.J. HUGHES, N. PIECHAUD, T.D. NICKELL, H. ELLWOOD, N. ASKEW, C. JENKINS and E. MANCA (2015) A Deep-sea Section for the Marine Habitat Classification of Britain and Ireland. JNCC report 530. In: JNCC (2015) The Marine Habitat Classification for Britain and Ireland Version 15.03 [Online]. [Date accessed].
Available from: jncc.defra.gov.uk/MarineHabitatClassification
ISSN 0963 8901