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Marine Habitat Classification


1 result for 'CR.MCR.EcCr.CarSwi.LgAs'

   CR.MCR.EcCr.CarSwi.LgAs  Caryophyllia smithii, Swiftia pallida and large solitary ascidians on exposed or moderately exposed circalittoral rock

This variant typically occurs on exposed to moderately wave-exposed, circalittoral bedrock and boulders rock subject to mainly weak tidal streams and has a thin layer of silt present. It is found predominantly from 10-30m water depth. From afar, this biotope is mostly distinguished by the frequently occurring seafan Swiftia pallida, encrusting red algae and the abundant cup coral Caryophyllia smithii. This biotope has quite an impoverished appearance, compared with SwiLgAs which has a strong sponge component. Other species present are typically in low abundance. Echinoderms such as Echinus esculentus, Antedon bifida, Antedon petasus, Leptometra celtica, Marthasterias glacialis, Luidia ciliaris and Asterias rubens may be recorded. Large hydroids such as Nemertesia antennina and Nemertesia ramosa may occasionally be seen in isolated clumps on the tops of boulders and rocky outcrops. The anthozoan Parazoanthus anguicomus may be recorded. Bryozoans such as Parasmittina trispinosa and Porella compressa are occasionally observed. The polychaete Spirobranchus triqueter may be observed encrusting the sides of rocks and boulders while occasional Alcyonium digitatum may also be seen. A small suite of large ascidians may be present, including Ascidia mentula, Clavelina lepadiformis, Ciona intestinalis, Diazona violacea and Ascidia virginea. Sponges are typically absent from this biotope, although Cliona celata may be recorded occasionally. The top shell Steromphala cineraria is usually present. Under boulders and overhangs, the squat lobster Munida rugosa can usually be seen hiding. All these records are from the west coast of Scotland (East coast of Lewis /Outer Hebrides).
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