Biodiversity & Conservation

Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock



Image Keith Hiscock - Circalittoral rock with Antedon bifida, hydroids and occasional solitary sea squirts. Image width ca 60 cm.
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Distribution map

CR.LCR.BrAs.AntAsH recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats

For a list of 2004 characterising species please see the JNCC website.

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
Important characterizing Antedon bifida Rosy featherstar
Important characterizing Nemertesia ramosa A hydroid
Important characterizing Ciona intestinalis A sea squirt
Important characterizing Clavelina lepadiformis Light bulb sea squirt


No one species dominates the biotope but comprises feather stars, represented by Antedon bifida, solitary ascidians and hydroids. Clavelina lepadiformis and Ciona intestinalis represent the ascidians and Nemertesia ramosa the hydroids.

Additional information

This review can be cited as follows:

Hill, J.M. 2001. Antedon spp., solitary ascidians and fine hydroids on sheltered circalittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/11/2015]. Available from: <>