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SS.SMx.SMxVS.CreMed
Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment

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Habitat (physical) description

Distribution

 Salinity: Variable (18-35 ppt) 
 Wave exposure: Very sheltered, Extremely sheltered 
 Tidal streams: Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) 
 Substratum: Mixed muddy sediment 
 Zone: Infralittoral 
 Depth Band: 0-5 m, 5-10 m, 10-20 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.

Previous code

This biotope occurred in previous versions of the classification as:
IMX.CreAph - Version: 97.06

Distribution of habitat SS.SMx.SMxVS.CreMed  Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral mixed sediment
Distribution of habitat SS.SMx.SMxVS.CreMed Crepidula fornicata and Mediomastus fragilis in variable salinity infralittoral 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

Variable salinity mixed sediment characterised by the slipper limpet Crepidula fornicata and the polychaetes Mediomastus fragilis and Aphelochaeta marioni. Other numerically important taxa include the oligochaetes Tubificoides benedii, syllids such as Exogone naidina and Sphaerosyllis, and Nephtys hombergii. Lepidonotus squamatus and Scoloplos armiger may also be common. Shell debris and cobbles are colonised by the ascidians Ascidiella aspersa, Ascidiella scabra, Molgula sp. and Dendrodoa grossularia (the ascidians may not be recorded adequately by remote infaunal survey techniques).

Situation

This biotope occurs in the lower estuary where currents allow a stable environment to develop. It is associated with oyster beds and relict oyster beds, (Ost) in southern England and Wales. It may be found adjacent to or in conjunction with AphTubi and AphPol. It may be associated with VsenAsquAps and possibly form a component of SundAasp.

Temporal variation

No temporal data available.

Similar biotopes

SS.SMx.IMx.CreAsAnCreAsAn is found in more exposed marine areas with a lower silt content and in fully marine conditions
SS.SMu.SMuVS.AphTubiCreMed It may be separated from AphTubi by the relative abundances of the slipper limpet Crepidula fornicata in addition to A. marioni.
SS.SMx.SMxVS.AphPolCreMed may be distinguished from AphPol by the abundance of C. fornicata and its sediment characteristics

Characterising Species

Taxa Frequency Typical Abundance % Contribution to similarity Abundance (no.2)
Hydrozoa P 5
Harmothoe impar C 2 18
Lepidonotus squamatus C 2 21
Exogone naidina F 4 288
Sphaerosyllis F 4 183
Nephtys C 2 29
Nephtys hombergii C 3 36
Scoloplos armiger A 2 28
Polydora ciliata C 2 53
Aphelochaeta marioni C 11 940
Caulleriella zetlandica F 1 95
Cirriformia tentaculata C 1 37
Tharyx killariensis F 1 89
Capitella capitata F 1 75
Mediomastus fragilis C 8 320
Melinna palmata C 1 54
Tubificoides benedii C 7 219
Tubificoides pseudogaster F 1 91
Tubificoides swirencoides C 2 588
Carcinus maenas A 1 12
Carcinus maenas O 7
Crepidula fornicata A 11 234
Crepidula fornicata C 85
Abra alba C 1 33

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