Many large coral heads in tropical waters are decorated with Christmas tree worms (Spirobranchus giganteus), which occur in a huge variety of colors. The worm lives in a calcareous 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 safety, the worm can also plug its tube with a small plate called an operculum.

(Photo source 1, 2, 3, 4)

Christmas-tree worms live attached to the bottom in hard tubes that they cement into coral reefs. They feed by filtering plankton from the water, using their beautiful double spiral of tentacles.

Christmas Tree Worms

Photograph by Jean Kunzelman

Christmas Tree Worm (Spirobranchus giganteus)

Length: 3cm

Location: Reefs throughout the tropics

fyeah-seacreatures:

The Christmas Tree Worm (Spirobranchus giganteus) is a colorful marine worm with beautiful, spiraling plumes that resemble a fir tree. These animals are colorful, and can be red, orange, yellow, blue and white. These worms lives on tropical coral reefs throughout the world.
The Christmas tree worm’s plumes are used for feeding and respiration. These worms use their plumes to catch plankton and other small particles passing in the water. Cilia then pass the food to the worm’s mouth.

(via ocean-ology)