EUNIS habitat classification 2012 amended 2019 > A - Marine habitats > A1 - Littoral rock and other hard substrata > A1.4 - Features of littoral rock > A1.44 - Communities of littoral caves and overhangs > A1.447 - Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves

Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves

English name: 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 A1.4461.

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code A1.447
Bern Convention Included in a Resolution 4 habitat type at a higher level (A1.44)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Actinia equina
Invertebrates Balanus crenatus
Invertebrates Balanus perforatus
Invertebrates Botryllus schlosseri
Invertebrates Corynactis viridis
Invertebrates Dynamena pumila
Invertebrates Grantia compressa
Invertebrates Halichondria panicea
Invertebrates Metridium senile
Invertebrates Pomatoceros triqueter
Invertebrates Semibalanus balanoides
Invertebrates Umbonula littoralis
Species scientific name English common name Species group
Actinia equina Invertebrates
Balanus crenatus Invertebrates
Balanus perforatus Invertebrates
Botryllus schlosseri Invertebrates
Corynactis viridis Invertebrates
Dynamena pumila Invertebrates
Grantia compressa Invertebrates
Halichondria panicea Invertebrates
Metridium senile Invertebrates
Pomatoceros triqueter Invertebrates
Semibalanus balanoides Invertebrates
Umbonula littoralis Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 LR.FLR.CvOv.SpByAs Sponges, bryozoans and ascidians on deeply overhanging lower shore bedrock or caves source
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type
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
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