‘Rocking around the Christmas Tree
Have a happy holiday
Everyone’s dancing merrily
In a new old fashioned way’ Brenda Lee
- Length: Up to 3cm tall
- Depth: 0-30m or sometimes more
- Habitat: Living coral heads
- Distribution: Shallow reef waters throughout the tropics
The worm is suitably named; both it’s Latin and common names refer to the two spiral structures, seen by divers. The multicoloured spirals are merely the worm’s respiratory structures. The worm’s most distinct features are two ‘crowns’ shaped like Christmas Trees. While these are primarily feeding structures S.Giganteus also uses them for respiration.
Many large coral heads in tropical waters are decorated with Christmas Tree Worms, which occur in a huge variety of colours. The worm lives in a calcaeous tube buried in the coral and extends neat, twin spirals of feeding tentacles above the coral surface. If disturbed, the worm pulls back into its tube in a fraction of a second. For added protection the worm can plug its tube with a small plate called an operculum.