The Christmas Tree Worm

Scientifically that are called spirobranchus giganteus, but they are better known by their colloquial name — Christmas tree worm. The worm is so called not because they feed on fig trees but because they look like them.

The spirobranchus giganteus live in the ocean and sports two magnificent spirals of plumes that protrude from its tube-like body and which look like tiny Christmas trees. These plumes are composed of hair-like appendages called radioles that radiate from the worm’s central spine, and help the animal to grab food, which typically consists of microscopic plants, or phytoplankton, floating in the water. The plumes are also used for respiration. Measuring less than 4 cm in height, they come in many colors including orange, yellow, blue, and white and, are easily spotted due to their shape, beauty, and color.

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Photo credit: Matt Kieffer/Flickr

The Christmas tree worm doesn’t like to move about much. Once they find a good place on a live calcareous coral, they burrow a hole and live their for the rest of their lives, occasionally emerging from their home to catch passing plankton with their fully extended plumes. They are very sensitive to disturbances and will rapidly retract into their burrows at the slightest touch or passing shadow.

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