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Marine Habitat Classification

Description of biotope or habitat type

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   Kurtiella bidentata and Abra spp. in infralittoral sandy mud

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Very sheltered
Tidal streams Very weak (negligible)
Substratum Muddy sands and sandy muds
Zone Infralittoral
Depth Band 0-5 m, 5-10 m, 10-20 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.ISaMu.KurAbr <I>Kurtiella bidentata</I> and <I>Abra</I> spp. in infralittoral 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.


Cohesive sandy mud, sometimes with a small quantity of shell in shallow water may contain the bivalves Kurtiella bidentata and Abra spp. (typically A. alba and A. nitida). Other characteristic taxa may include Scoloplos armiger, Mya sp., and Thyasira flexuosa. Tube building amphipods are also characteristic of this biotope in particular Ampelisca spp. and Aoridae such as Microprotopus maculatus. This biotope may also be compared with similar biotopes such as SS.SSa.CMuSa.AalbNuc, SS.SMx.CMx.KurThyMx or SS.SMu.ISaMu.MelMagThy.


This biotope is generally found in sheltered marine inlets or sea lochs such as Strangford Lough.

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
Nematoda 15 Frequent 81-100%
Abra alba 11 Common 61-80%
Scoloplos armiger 10 Super abundant 61-80%
Kurtiella bidentata 9 Frequent 81-100%
Ampelisca brevicornis 6 Common 41-60%
Mya 3 Common 61-80%
Abra nitida 2 Common 41-60%
Ampelisca tenuicornis 2 Frequent 41-60%
Cirratulidae 2 Common 41-60%
Microprotopus maculatus 2 Frequent 21-40%
Nephtys hombergii 2 Common 21-40%
Thyasira flexuosa 2 61-80%
Aoridae 1 Frequent 41-60%
Arenicola marina 1 21-40%
Capitella capitata 1 Frequent 21-40%
Dexamine thea 1 Frequent 41-60%
Mediomastus fragilis 1 Frequent 21-40%
Melinna palmata 1 Common 21-40%
Nephtys kersivalensis 1 Common 21-40%
Pariambus typicus 1 41-60%

Similar biotopes or habitat types

SS.SMu.ISaMu.KurAbr is similar to SS.SMu.ISaMu.AmpPlon but differs in the variety and abundance of amphipods and is found in muddier sediments in sheltered sealochs such as Strangford Lough. It is possible that these two biotopes are actually part of a wider biotope which contains more than one entity depending on its geographic location and prevailing environmental conditions.

Classification history of this biotope or habitat type

Classification version Code Habitat name
2015 (15.03) SS.SMu.ISaMu.MysAbr Mysella bidentata and Abra spp. in infralittoral sandy mud
2004 (04.05) SS.SMu.ISaMu.MysAbr Mysella bidentata and Abra spp. in infralittoral sandy mud

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