Biodiversity & Conservation

Sabellaria spinulosa crusts on silty turbid circalittoral rock



Image Anon. - Sabellaria spinulosa crusts on silty turbid circalittoral rock. Image width ca 10 cm.
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Distribution map

CR.MCR.As.MolPol.Sab recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats

Species indicative of sensitivity

To assess the sensitivity of the biotope, the sensitivity of component species is reviewed. Those species that are considered to be particularly indicative of the sensitivity of the biotope, and for which research has been undertaken in detail are shown below (see selection criteria). The biology of other component species of the biotope is also taken into account wherever information is known to the researcher.

Community Importance Species name Common Name
Key structural Sabellaria spinulosa Ross worm
Important functional Urticina felina Dahlia anemone
Important functional Ophiothrix fragilis Common brittlestar


In this biotope, Sabellaria spinulosa forms an almost complete crust on rocky substrata. This crust may increase structural diversity through creation of crevices, nooks and crannies. The worm tubes themselves provide an alternative substratum for settlement or attachment of other species and burrowing species may live in thick crusts. There are few characteristic species in this biotope and fauna found on Sabellaria spinulosa probably reflects those species present in near-by rocky biotopes. Ophiothrix fragilis, although not always present in this biotope, may occur in high densities but is more typical in lower densities located round the lobes of Alcyonium digitatum etc (Sköld, 1998). The suspension feeding habits of Ophiothrix fragilis can have an important role in coastal environments, removing substantial amounts of suspended sediment (Davoult & Gounin, 1995) and also in nutrient exchange at the water-sediment interface (Lefebvre & Davoult, 1997). Aggregations of Ophiothrix fragilis also modify the complexity of the habitat providing structure and shelter. In some high water flow, coarse sediment communities Urticina felina, along with Ophiothrix fragilis and Alcyonium digitatum (also present in the biotope in NE England) can make up a large percentage of the biomass (Mign & Davoult, 1995; Mign & Davoult, 1997). Although less important in this biotope, Urticina felina is still an important characterizing species as a passive carnivore and with a potential role in nutrient exchange.

Additional information

Although there are two records of the MCR.Sspi biotope in the MNCR survey database, species richness information is available for only one with 42 species being noted. In the study undertaken by George & Warwick (1985) of aggregations most likely on cobbles and pebbles, 24 different species were recorded but only 'countable' species were included.

This review can be cited as follows:

Jackson, A. & Hiscock, K. 2006. Sabellaria spinulosa crusts on silty turbid circalittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 19/04/2014]. Available from: <>