2. Données et outils
  3. Rechercher un habitat
  4. MC1-232 - Grandes ascidies solitaires et éponges dressées sur roche du circalittoral abritée en Atlantique
  5. Description
MC1-232 - Grandes ascidies solitaires et éponges dressées sur roche du circalittoral abritée en Atlantique

Large solitary ascidians and erect sponges on wave-sheltered Atlantic circalittoral rock
MC1-231 - Ascidies solitaires, dont Ascidia mentula et Ciona intestinalis, sur roche du circalittoral abritée des vagues en Atlantique
MC1-233 - Antedon spp., ascidies solitaires et fins hydraires sur roche du circalittoral abritée en Atlantique

Classification des habitats EUNIS 2022

Descriptif de l'habitat

MC1-232 is characteristic of the wave-sheltered conditions found in the Kenmare River on the west coast of Ireland. This biotope is typically found on silty circalittoral bedrock and boulders in wave-sheltered channels subject to varying amounts of tidal flow. These fully marine inlets and channels have steep, often vertical sides with small terraces or ledges. This biotope, characterised by erect sponges and large solitary ascidians, appears to be biologically diverse. A diverse ascidian fauna is generally present, including Ascidia mentula, Aplidium punctum, Corella parallelogramma, Ascidia virginea, Botryllus schlosseri, Clavelina lepadiformis and Ciona intestinalis. An equally diverse sponge fauna, with massive erect sponges particularly noticeable, compliments these species. Dominant species include Esperiopsis fucorum, Dysidea fragilis, Tethya aurantium, Polymastia boletiformis, Raspailia ramosa, Stelligera stuposa, Polymastia mamilliaris and Pachymatisma johnstonia. Other sponges present are Suberites carnosus, Haliclona fistulosa, Stelligera rigida, Mycale rotalis, Haliclona simulans, Iophon hyndmani and Hemimycale columella. Various sponge crusts may also be present but in most cases in lower abundances. Other significant components of the community include the cup coral Caryophyllia smithii and various echinoderms, including the sea urchin Echinus esculentus and the starfish Henricia oculata and Marthasterias glacialis. Small isolated clumps of Nemertesia antennina and individual Alcyonium digitatum may be seen, whilst the top shell Calliostoma zizyphinum may also be present. At present, there are relatively few records in this biotope, as it is only reported from around the south-western coast of Ireland, where sponge diversity is very high.
Situation: Due to the sheltered nature of the biotope, this unit is usually situated on bedrock/boulder outcrops associated with mud slopes and plains. Typical species found within these circalittoral muds include the seapen Virgularia mirablis and the anemone Pachycerianthus multiplicatus. In the infralittoral zone, sheltered kelp biotopes such as MB3-211 with Laminaria saccharina occur frequently. In areas where there is a slightly stronger tidal-stream, the circalittoral muddy plains become more muddy gravel plains and slopes. Typical species found within these habitats include the anemones Mesacmaea mitchellii and Aureliana heterocera. When tidal-streams becomes negligible, but with similar wave-sheltered conditions, you tend to find MC1-2211 biotopes occurring, especially in the same geographical location (around south-west/west Ireland) as MC1-232.

Bibliographie

European Topic Centre on Biological Diversity 2022. EUNIS marine habitat classification 2022 including crosswalks. Table Excel. (Source)