Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock
Quick facts
EUNIS habitat type | code A4.313 |
---|---|
Bern Convention | Included in a Resolution 4 habitat type at a higher level (A4) |
Description (English)
This biotope is typically found on silty boulder or rock slopes, in the sheltered parts of sealochs, subject to weak or very weak tidal currents. The seabed consists of smooth, silty bedrock or boulders, often as outcrops on mixed muddy sediment. There are often small vertical faces on the sides of rock ridges, and at few sites, there may be more extensive steep or vertical bedrock. In sharp contrast to the barren, grazed appearance of A4.3111, the species composition of unit A4.313 is quite diverse, although no one phyla dominates. A wide range of encrusting species may be found, including the brachiopod Neocrania anomala, the saddle oyster Pododesmus patelliformis, encrusting red algae and polychaetes (Pomatoceros triqueter and Protula tubularia). Other conspicuous species include crinoids on the tops of boulders (Antedon bifida, commoner in shallower water and Antedon petasus, commoner in deeper water), scattered solitary and colonial ascidians (Ascidia mentula, Ascidia virginea, Corella parallelogramma, Clavelina lepadiformis and Ciona intestinalis) and tufts of fine hydroids (Kirchenpaueria pinnata, Nemertesia antennina, Obelia dichotoma and Halceum halecinum). The cup coral Caryophyllia smithii and the crustose bryozoan Parasmittina trispinosa are all typically present, as are a wide range of echinoderms, including the sea urchin Echinus esculentus, the starfish Asterias rubens and Crossaster papposus, and the brittlestars Ophiothrix fragilis and Ophiura albida. Other species recorded are the squat lobster Munida rugosa, the hermit crab Pagurus bernhardus and the chiton Tonicella marmorea.
Situation: The range of biotopes shallower and deeper than A4.313 is typical of a sheltered sealoch. Silted kelp biotopes (e.g. units A3.312, A3.313) are typically found shallower than A4.313 in the infralittoral zone. Deeper than A4.313, the boulder slope typically grades into a muddy slope or plain (units A5.3 or A5.4), along with fauna commonly associated with soft-sediments (e.g. seapens and the mud snail Turritella).
Source: EUNIS habitat classification
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Species scientific name | English common name | Species group |
---|---|---|
Antedon bifida | Invertebrates | |
Ascidia mentula | Invertebrates | |
Asterias rubens | Invertebrates | |
Caryophyllia smithii | Invertebrates | |
Ciona intestinalis | Invertebrates | |
Clavelina lepadiformis | Invertebrates | |
Echinus esculentus | Invertebrates | |
Kirchenpaueria pinnata | Invertebrates | |
Nemertesia antennina | Invertebrates | |
Neocrania anomala | Invertebrates | |
Obelia dichotoma | Invertebrates | |
Ophiothrix fragilis | Invertebrates | |
Ophiura albida | Invertebrates | |
Protula tubularia | Invertebrates |
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
Marine Habitat Classification Britain/Ireland 0405 | CR.LCR.BrAs.AntAsH | <I>Antedon</I> spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | source |
CORINE Land Cover | 5.2.3. | Sea and ocean | n/a |
History
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 200410 | A4.313 | Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | same |
EUNIS Habitat Classification 200308 | A3.711 | Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | same |
EUNIS Habitat Classification 200202 | A3.711 | Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | same |
EUNIS Habitat Classification 199910 | A3.711 | Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | same |
MNCR BioMar 97.06 (Britain & Ireland) | SCR.BrAs.AntAsH | Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock | same |