Chthamalus montagui and Chthamalus stellatus on exposed upper eulittoral rock

Quick facts

EUNIS habitat type code MA12221
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Description (English)

Very exposed to moderately exposed upper and mid eulittoral bedrock and boulders characterised by a dense community of barnacles, including Chthamalus montagui, Chthamalus stellatus and Semibalanus balanoides, and the limpet Patella vulgata. Damp cracks and crevices in the rock provide a refuge for small individuals of the mussel Mytilus edulis, and the winkles Melarhaphe neritoides and Littorina saxatilis. These crevices can also be occupied by encrusting coralline algae and the anemone Actinia equina. Patches of the black lichen Verrucaria maura and the green seaweed Enteromorpha intestinalis may be present, though in low abundance (Occasional). Shaded vertical littoral fringe and upper eulittoral bedrock may be characterised by the shade-tolerant red seaweeds Catenella caespitosa, Bostrychia scorpioides and/or Lomentaria articulata. Where the turf of C. caespitosa is well established, barnacles are rare. Geographical variation: There is much regional variation in the distribution and zonation of Chthamalus spp. On the west coast Chthamalus spp. dominate the upper eulittoral, often forming a distinct white band above a darker band of S. balanoides in the mid eulittoral zone. C. montagui is better adapted to resist desiccation and, therefore, extends further up the shore. In the south-west Chthamalus spp. can be the dominant barnacles throughout the eulittoral zone.
Situation: This unit is found below the black lichen Verrucaria maura (MA1-2131 or MA1-2132) on very exposed shores. It is found above the mussel Mytilus edulis and barnacles biotope (MA1-221). On slightly less exposed shores the wrack Fucus vesiculosus is able to survive and a mixed barnacle and F. vesiculosus biotope may occur (MA1-2232) beneath MA1-2221. On such moderately exposed shores MA1-2221 may still occur on steep and vertical faces, while fucoids dominate the flatter areas (MA1-2232), though these communities should not be confused with MA1-2232. On very sheltered sea lochs in Argyll, West Scotland Chthamalus spp. are unusually abundant in the upper eulittoral zone.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Enteromorpha intestinalis
Algae Fucus vesiculosus
Invertebrates Actinia equina
Invertebrates Chthamalus stellatus
Invertebrates Melarhaphe neritoides
Invertebrates Mytilus edulis
Invertebrates Patella vulgata
Species scientific name English common name Species group
Enteromorpha intestinalis Algae
Fucus vesiculosus Algae
Actinia equina Invertebrates
Chthamalus stellatus Invertebrates
Melarhaphe neritoides Invertebrates
Mytilus edulis Invertebrates
Patella vulgata Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A1.1121 Chthamalus montagui and Chthamalus stellatus on exposed upper eulittoral rock same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A1.1121 Chthamalus montagui and Chthamalus stellatus on exposed upper eulittoral rock same
EUNIS Habitat Classification 200308 A1.1121 Chthamalus spp. on exposed upper eulittoral rock narrower
EUNIS Habitat Classification 200308 A1.1123 Catenella caespitosa on overhanging, or shaded vertical, upper eulittoral rock narrower
EUNIS Habitat Classification 200202 A1.1121 Chthamalus spp. on exposed upper eulittoral rock narrower
EUNIS Habitat Classification 200202 A1.1123 Catenella caespitosa on overhanging, or shaded vertical, upper eulittoral rock narrower
EUNIS Habitat Classification 199910 A1.1123 Catenella caespitosa on overhanging, or shaded vertical, upper eulittoral rock narrower
EUNIS Habitat Classification 199910 A1.1121 Chthamalus spp. on exposed upper eulittoral rock narrower
MNCR BioMar 97.06 (Britain & Ireland) ELR.MB.BPat.Cat Catenella caespitosa on overhanging, or shaded vertical, upper eulittoral rock narrower
MNCR BioMar 97.06 (Britain & Ireland) ELR.MB.BPat.Cht Chthamalus spp. on exposed upper eulittoral rock narrower
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