Flustra foliacea, small solitary and colonial ascidians on tide-swept circalittoral bedrock or boulders

English name: Flustra foliacea, small solitary and colonial ascidians on tide-swept circalittoral bedrock or boulders

Quick facts

EUNIS habitat type code A4.1342
Bern Convention Included in a Resolution 4 habitat type at a higher level (A4)

Description (English)

This sub-biotope is typically found on the upper faces of exposed to moderately exposed, tide-swept, scoured, circalittoral bedrock or boulders. It most frequently occurs between 10-20m water depth. The biotope is characteristically dominated by dense Flustra foliacea with a variety of slightly scour/silt-tolerant species forming a dense turf. This turf is primarily composed of bryozoans (Alcyonidium diaphanum, Bugula flabellata, Bugula plumosa, Bicellariella ciliata) and hydroids (Tubularia indivisa, Nemertesia antennina, Sertularia argentea, Hydrallmania falcata, Abietinaria abietina). Where space permits, barnacles such as Balanus crenatus may be found encrusting on the rock surface. There may also be occasional crusts formed by the polychaete Sabellaria spinulosa, especially where the rock is most influenced by sand. Anthozoans which may be observed include Urticina felina, Sagartia elegans, whilst the soft coral Alcyonium digitatum may be recorded on the tops of boulders and bedrock ridges. A range of small solitary and colonial ascidians may be seen, including Polycarpa scuba, Dendrodoa grossularia, Molgula manhattensis, Botryllus schlosseri, Clavelina lepadiformis and polyclinids. Sponges found include Scypha ciliata, Cliona celata, Esperiopsis fucorum and Dysidea fragilis. Echinoderms such as Asterias rubens, Henricia oculata and Crossaster papposus may be seen on the rock surface. Other species found include the top shell Calliostoma zizyphinum, the crabs Cancer pagurus and Necora puber.
Situation: Above this variant, exposed kelp forest supporting Laminaria hyperborea is commonly found (unit A3.115). At locations where wave-exposure and/or tidal streams are less, this biotope may be replaced by Alcyonium digitatum and Securiflustra securifrons (unit A4.2143). Where the substrata changes to a less stable mixed substrata, then this biotope will be replaced by the sub-biotope A4.1343, with more `sediment' species such as Cerianthus lloydii and Chaetopterus variopedatus.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Algae Laminaria hyperborea
Invertebrates Abietinaria abietina
Invertebrates Alcyonidium diaphanum
Invertebrates Alcyonium digitatum
Invertebrates Asterias rubens
Invertebrates Balanus crenatus
Invertebrates Bicellariella ciliata
Invertebrates Botryllus schlosseri
Invertebrates Bugula flabellata
Invertebrates Bugula plumosa
Invertebrates Calliostoma zizyphinum
Invertebrates Cancer pagurus
Invertebrates Chaetopterus variopedatus
Invertebrates Clavelina lepadiformis
Invertebrates Cliona celata
Invertebrates Crossaster papposus
Invertebrates Dendrodoa grossularia
Invertebrates Dysidea fragilis
Invertebrates Esperiopsis fucorum
Invertebrates Flustra foliacea
Invertebrates Henricia oculata
Invertebrates Hydrallmania falcata
Invertebrates Molgula manhattensis
Invertebrates Necora puber
Invertebrates Nemertesia antennina
Invertebrates Polycarpa scuba
Invertebrates Sabellaria spinulosa
Invertebrates Sagartia elegans
Invertebrates Securiflustra securifrons
Invertebrates Sertularia argentea
Invertebrates Tubularia indivisa
Invertebrates Urticina felina
Species scientific name English common name Species group
Laminaria hyperborea Algae
Abietinaria abietina Invertebrates
Alcyonidium diaphanum Invertebrates
Alcyonium digitatum Invertebrates
Asterias rubens Invertebrates
Balanus crenatus Invertebrates
Bicellariella ciliata Invertebrates
Botryllus schlosseri Invertebrates
Bugula flabellata Invertebrates
Bugula plumosa Invertebrates
Calliostoma zizyphinum Invertebrates
Cancer pagurus Invertebrates
Chaetopterus variopedatus Invertebrates
Clavelina lepadiformis Invertebrates
Cliona celata Invertebrates
Crossaster papposus Invertebrates
Dendrodoa grossularia Invertebrates
Dysidea fragilis Invertebrates
Esperiopsis fucorum Invertebrates
Flustra foliacea Invertebrates
Henricia oculata Invertebrates
Hydrallmania falcata Invertebrates
Molgula manhattensis Invertebrates
Necora puber Invertebrates
Nemertesia antennina Invertebrates
Polycarpa scuba Invertebrates
Sabellaria spinulosa Invertebrates
Sagartia elegans Invertebrates
Securiflustra securifrons Invertebrates
Sertularia argentea Invertebrates
Tubularia indivisa Invertebrates
Urticina felina Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
Marine Habitat Classification Britain/Ireland 0405 CR.HCR.XFa.FluCoAs.SmAs <I>Flustra foliacea</I>, small solitary and colonial ascidians on tide-swept circalittoral bedrock or boulders 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 A4.1342 Flustra foliacea, small solitary and colonial ascidians on tide-swept circalittoral bedrock or boulders same
EUNIS Habitat Classification 200308 A3.6222 Flustra foliacea, small solitary and colonial ascidians on tide-swept circalittoral bedrock or boulders same
EUNIS Habitat Classification 200202 A3.6222 Flustra foliacea with hydroids, bryozoans and sponges on slightly tide-swept circalittoral mixed substrata same
EUNIS Habitat Classification 199910 A3.6222 Flustra foliacea with hydroids, bryozoans and sponges on slightly tide-swept circalittoral mixed substrata same
MNCR BioMar 97.06 (Britain & Ireland) MCR.ByH.Flu.HByS Flustra foliacea with hydroids, bryozoans and sponges on slightly tide-swept circalittoral mixed substrata same
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