Musculus discors beds on moderately exposed circalittoral rock
Quick facts
EUNIS habitat type | code A4.242 |
---|---|
Bern Convention | Included in a Resolution 4 habitat type at a higher level (A4) |
Description (English)
This biotope typically occurs on the upper faces of moderately exposed, moderately tide-swept bedrock, boulders and cobbles in slightly silty conditions. The mussel Musculus discors occurs in dense mats and occasionally completely coats all available surfaces. There is also often a layer of pseudofaeces, forming a thick, silty matrix. A relatively diverse fauna of cushion and branching sponges is often present on rocky outcrops and other hard substratum that is free of mussels. These include Tethya aurantium, Scypha ciliata, Pachymatisma johnstonia, Dysidea fragilis, Cliona celata and Stelligera stuposa. There may be isolated clumps of silt-tolerant bryozoans such as Flustra foliacea and Bugula plumosa. Various species may be observed on top of the mussels, including Asterias rubens, Crossaster papposus and the brittlestar Ophiura albida. Occasional Alcyonium digitatum and clumps of the hydroid Nemertesia antennina are found attached to rocky outcrops and boulders whilst the anemone Urticina felina may be seen in crevices in the rock or on gravely patches between boulders. Colonial ascidians such as Clavelina lepadiformis and didemnids may occasionally be present. A wide range of seaweeds may be present, including Dictyota dichotoma, Plocamium cartliagineum, Dictyopteris membranacea, Cryptopleura ramosa and Heterosiphonia plumosa. The crab Cancer pagurus may be observed in crevices. The majority of the records for this biotope are from the Lleyn Peninsula.
Source: EUNIS habitat classification
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Species scientific name | English common name | Species group |
---|---|---|
Dictyota dichotoma | Algae | |
Alcyonium digitatum | Invertebrates | |
Asterias rubens | Invertebrates | |
Cancer pagurus | Invertebrates | |
Clavelina lepadiformis | Invertebrates | |
Cliona celata | Invertebrates | |
Dysidea fragilis | Invertebrates | |
Flustra foliacea | Invertebrates | |
Musculus discors | Invertebrates | |
Nemertesia antennina | Invertebrates | |
Ophiura albida | Invertebrates | |
Pachymatisma johnstonia | Invertebrates | |
Tethya aurantium | Invertebrates |
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
Marine Habitat Classification Britain/Ireland 0405 | CR.MCR.CMus.Mdis | <I>Musculus discors</I> beds on moderately exposed circalittoral rock | source |
CORINE Land Cover | 5.2.3. | Sea and ocean | n/a |
History
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 200410 | A4.242 | Musculus discors beds on moderately exposed circalittoral rock | same |
EUNIS Habitat Classification 200308 | A3.642 | Musculus discors beds on moderately exposed circalittoral rock | same |
EUNIS Habitat Classification 200202 | A3.642 | Musculus discors beds on moderately exposed circalittoral rock | same |
EUNIS Habitat Classification 199910 | A3.642 | Musculus discors beds on moderately exposed circalittoral rock | same |
MNCR BioMar 97.06 (Britain & Ireland) | MCR.M.Mus | Musculus discors beds on moderately exposed circalittoral rock | same |