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Animal profile

Christmas Tree Worm

Spirobranchus giganteus

PolychaetaEmbedded in living stony coral heads on shallow tropical reefs

Field profile

The Christmas tree worm is a small tube-dwelling polychaete whose two spiral crowns of feeding radioles project from a coral head. The body itself is hidden inside a calcareous tube bored into the coral skeleton. Crowns come in a wide range of colours.

Scope note

This is an editorial profile, not a diagnostic field-identification guide or a substitute for current conservation assessments. Follow the cited sources on each fact for the evidence trail.

Published field notes

2026-03-31

Christmas Tree Worm

Its Christmas trees are feeding and breathing organs

The two coloured spirals are crowns of feathery radioles that filter plankton from the water and exchange gas. Almost all of the animal is hidden inside a calcareous tube bored into a living coral head.

Read with evidence →

Christmas Tree Worm | Daily Animal Facts