- Kingdom: Animalia
- Phylum: Annelida
- Class: Polychaeta
- Subclass: Sedentaria
- Order: Sabellida
- Family: Serpulidae
- Subfamily: Spirorbinae
- Scientific name: Circeis spirillum
- Norwegian: korketrekkerorm
The tiny, white and sometimes translucent tube is coiled counterclockwise, in contrast to another common tubeworm, S. spirorbis. The orange body has up to 23 segments and can sometimes be seen through the tube wall. The overall coil diameter is less than 3 mm. The crown is red.
On shallow locations, just below the tidal zone, it is usually found on algae. On greater deeps, it thrives on hydroids.
It is widespread on the northern hemisphere, both in the Atlantic and Pacific Ocean.