Book 6, Question 96
Why Do Christmas-Tree Worms Vanish?
Those little colorful trees on a Christmas-tree worm are really its gills and feeding fans. The worm lives safely in a tube in the coral. If a shadow or ripple says danger, it zips back inside in a flash!
From the book
Page from A Million Whys Book 6
More fun facts
- Christmas tree worms live on tropical coral reefs around the world.
- The little trees are really the worm's feathery gills, shaped like a pair of colorful spirals.
- When a shadow passes over, the gills drop down into a tube where the rest of the worm hides.
- Christmas tree worms come in many bright colors.
- Scientist Michael Bok says their eyes are in a really silly place, among the feathery gills.
- Some Christmas tree worms live buried in brain coral for their whole lives.
Sources: NOAA Ocean Service, Science News Explores, National Park Service
Questions kids ask
Why do Christmas tree worms disappear?
When a shadow looms, they pull their gills down into a protective tube.