Invertebrates - Spirorbis borealis
Spirorbis borealis
Tube diameter up to 3mm

A curious little annelid worm which lives inside a spirally arranged, calcareous white tube. Small groups of these tubes can be observed on the fronds of various seaweeds such as serrated wrack; also found on rocks and mollusc shells on the lower shore. Common and widespread around the coasts of Britain and Ireland.