Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves
Description (English)
Overhanging, and shaded vertical, bedrock on the lower shore and in lower shore caves, which is not subject to appreciable wave-surge, characterised by crusts of bryozoans including Umbonula littoralis, sponges such as Grantia compressa, Halichondria panicea, Scypha ciliata and Hymeniacidon perleve and the ascidian Botryllus schlosseri. On overhangs, the hydroid Dynamena pumila hangs in distinct form from overhanging rock. The barnacles Balanus crenatus, Balanus perforatus (sometimes at high densities) and Semibalanus balanoides, and the calcareous tube-forming polychaetes Spirorbis spp. and Pomatoceros triqueter can be present as well. Certain species which are generally confined to the sublittoral, including the anemones Metridium senile and Corynactis viridis, may be found in the lower shore caves and overhangs. Littoral species such as Actinia equina are also present. The only algae present are coralline crusts. The list of characterising species partly reflects the variation in the species composition between individual overhangs and caves although this biotope can have a high species richness.
Situation: This biotope is found in the lower eulittoral and sublittoral fringe in less wave-surged conditions than that of unit MA1-2761.
Source: EUNIS habitat classification
Quick facts
EUNIS habitat type | code MA1277 |
---|---|
Relation to | Resolution 4 habitat type (used for designation of Emerald sites) |
Legal status
Relation to other habitat types mentioned in legal instruments
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Species scientific name | English common name | Species group |
---|---|---|
Actinia equina | Invertebrates | |
Balanus perforatus | Invertebrates | |
Botryllus schlosseri | Invertebrates | |
Corynactis viridis | Invertebrates | |
Halichondria panicea | Invertebrates |
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 2007 (revised descriptions 2012) | A1.447 | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves | same |
History
Classification | Code | Habitat type name | Relationship type | Comment |
---|---|---|---|---|
EUNIS Habitat Classification 200410 | A1.447 | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves | same | |
EUNIS Habitat Classification 200308 | A1.613 | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves | same | |
EUNIS Habitat Classification 200202 | A1.613 | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock | same | |
EUNIS Habitat Classification 199910 | A1.613 | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock | same | |
MNCR BioMar 97.06 (Britain & Ireland) | LR.Ov.SByAs | Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock | same |