Sabellaria spinulosa lives in a tube made of shell fragments and coarse sand cemented together with mucus.

The tube has a circular cross section and can be closed by an operculum formed by bristles growing on the head of the worm.

[1] Sabellaria spinulosa is a filter feeder, extending its feeding tentacles to catch plankton and detritus that are brought within its reach by the current.

Where reefs exist, they provide a biodiverse habitat for a large number of invertebrates and juvenile fish.

They are often dominated by the presence of crustaceans, especially the porcelain crab (Pisidia longicornis) and the pink shrimp (Pandalus montagui), which feed on the worms and on other invertebrates which shelter in the reefs.

For example, in the Wadden Sea, trawling for pink shrimp (Pandalus montagui) [7] broke up the reefs and destroyed the fishery as well.