• Kingdom: Animalia
  • Phylum: Annelida
  • Class: Polychaeta
  • Subclass: Sedentaria
  • Order: Sabellida
  • Family: Serpulidae
  • Scientific name: Hydroides norvegicus
  • Norwegian: hvitrørmark


The body length rarely exceeds 3 cm, but may include as many as 100 segments. The tube is white or brown, usually white at near the opening. The tube diameter is approximately 3 mm. The tentacles have white and red bands.


It prefers hard substrate, well below the tidal zone.


It is widespread in the North-East Atlantic Ocean, the Mediterranean and the Black Sea.