Protula tubularia reaches 8 cm deployed crown. Small fanworm (Polychaeta, Serpulidae) Mediterranean and temperate Atlantic with cylindrical white calcareous tube fixed on rocks, two distinctive symmetric salmon-pink to white loop-shaped branchial crowns (no operculum unlike Spirobranchus). Lives from 1 to 50 m on hard substrates and coralligenous of Mediterranean. Discreet but common. Macro photo subject for classic tubicolous Polychaeta.

