EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A5 - Sublittoral sediment > A5.3 - Sublittoral mud > A5.34 - Infralittoral fine mud > A5.343 - Philine aperta and Virgularia mirabilis in soft stable infralittoral mud

Philine aperta and Virgularia mirabilis in soft stable infralittoral mud

English name: Philine aperta and Virgularia mirabilis in soft stable infralittoral mud

Quick facts

EUNIS habitat type code A5.343
Bern Convention Included in a Resolution 4 habitat type at a higher level (A5)

Description (English)

Physically very stable muds, occasionally with small stones, with a high proportion of fine material (typically greater than 80 %) may contain the opisthobranch Philine aperta and the seapen Virgularia mirabilis. These muds typically occur in shallow water down to about 12-15 m where significant seasonal variation in temperature is presumed to occur. This habitat is restricted to the most sheltered basins in, for example, sealochs. Although most records suggest full salinity conditions are prevalent, some sites may be subject to variable salinity. Philine aperta is the most characteristic species of this habitat, occurring in high densities at many sites, whilst Virgularia mirabilis, a species found more widely in muddy sediments, appears to reach its highest densities in this shallow mud but may not be present in all examples of this biotope. Other conspicuous species found in this shallow muddy habitat include Cerianthus lloydii, Pagurus bernhardus, Sagartiogeton spp. and Hydractinia echinata. Burrowing crustacean megafauna, characteristic of deeper mud, are rare or absent from this shallow sediment although Nephrops norvegicus may sometimes be recorded. This biotope has been primarily recorded on the basis of its epifauna and a few conspicuous infauna. Little data exists on the infaunal component of this biotope but it may include Nephtys spp., spionid polychaetes, Ampelisca spp. and the bivalves Nucula spp., Thyasira flexuosa, Mysella bidentata and Abra spp. In the south of Great Britain, the polychaete Sternaspis scutata is also characteristic of this biotope. This polychaete is rare in Great Britain (Sanderson 1996). Indeed, this southern variant of the biotope is very restricted in the UK to Portland Harbour but is known to occur further south in the Gulf of Gascony and the Mediterranean (Glemarec 1973; Dauvin et al. 1994).
Temporal variation: It is possible that this biotope is a temporal variant of other subunits of A5.3. The key species, Philine aperta, may be highly variable from year to year The sediment may also be covered by a diatom film at certain times of the year

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Hydractinia echinata
Invertebrates Mysella bidentata
Invertebrates Nephrops norvegicus
Invertebrates Pagurus bernhardus
Invertebrates Philine aperta
Invertebrates Sternaspis scutata
Invertebrates Thyasira flexuosa
Invertebrates Virgularia mirabilis
Species scientific name English common name Species group
Hydractinia echinata Invertebrates
Mysella bidentata Invertebrates
Nephrops norvegicus Invertebrates
Pagurus bernhardus Invertebrates
Philine aperta Invertebrates
Sternaspis scutata Invertebrates
Thyasira flexuosa Invertebrates
Virgularia mirabilis Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 SS.SMu.IFiMu.PhiVir <I>Philine aperta</I> and <I>Virgularia mirabilis</I> in soft stable infralittoral mud source
CORINE Land Cover 5.2.3. Sea and ocean n/a
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 200410 A5.343 Philine aperta and Virgularia mirabilis in soft stable infralittoral mud same
EUNIS Habitat Classification 200308 A4.313 Philine aperta and Virgularia mirabilis in soft stable infralittoral mud same
EUNIS Habitat Classification 200202 A4.313 Philine aperta and Virgularia mirabilis in soft stable infralittoral mud same
EUNIS Habitat Classification 199910 A4.313 Philine aperta and Virgularia mirabilis in soft stable infralittoral mud same
MNCR BioMar 97.06 (Britain & Ireland) IMU.MarMu.PhiVir Philine aperta and Virgularia mirabilis in soft stable infralittoral mud same
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