Alderina imbellis

Alderina imbellis is an encrusting bryozoan that forms broad irregular sheets over various substrates. The species is found in cool temperate environments from the northern coasts of Spain to Shetland, Norway and the Faroe Isles.
Alderina imbellis occurs in subtidal offshore waters, typically on coarse, mixed grounds. It is able to colonise a range of substrates including stones and shells. It may also be found on living specimens of whelks e.g. Buccinum undatum, the bivalve mollusc Anomia and king scallops, Pecten maximus.