Christmas Tree Worm
The Christmas tree worm (Spirobranchus giganteus) is a tube-dwelling marine worm that lives embedded in living coral. Its two spiral crowns of feathery tentacles, in many colors, retract instantly into the tube when disturbed.
The Christmas tree worm (Spirobranchus giganteus) is a tube-dwelling marine worm that lives embedded in living coral. Its two spiral crowns of feathery tentacles, in many colors, retract instantly into the tube when disturbed.
🧬 Field Guide Specimen: Open Christmas Tree Worm in the CRV Science Field Guide to log the specimen, see its place among the Lophotrochozoa lineages in the Cladogram Explorer, and test your recall in the Red List conservation game.
Crowns for Breathing and Feeding
The plumes act as gills, and fine cilia on them sweep plankton toward the mouth. The worm withdraws into its tube and plugs the opening with a spiny trapdoor, the operculum, at the first sign of danger.
Living in Coral
The larva settles on a live coral colony and secretes a tube, and the coral grows around it, so the worm ends up in a burrow within the coral's skeleton. The worm benefits from a safe home, and the coral gets some protection from other fouling organisms.
A Colorful Population
Colors vary widely in the same reef, from orange and yellow to blue and white, and are not linked to sex. Annelids like this worm are related to earthworms and leeches.
Christmas Tree Worm at a Glance
| Property | Value |
|---|---|
| Scientific name | Spirobranchus giganteus |
| Kingdom | Animalia |
| Phylum | Annelida |
| Class | Polychaeta |
| Order | Sabellida |
| Family | Serpulidae |
| Field Guide group | Lophotrochozoa: Worms, Shells & Allies |
| Diagnostic feature (Field Guide) | Pair of brightly colored spiral radiolar crowns protruding from calcium carbonate tubes burrowed into living coral heads. |
| Class | Polychaeta |
| Habitat | Embedded in living coral |
See Also
- Staghorn Coral — a reef host
- Lugworm — another marine annelid