Christmas Tree Worm

Christmas tree-shaped serpulid tube-dwelling worm with magnificent twin spirals of plumes used for feeding and respiration.
They come in many colors including orange, yellow, blue, and white and, are small with an average 3.8 cm in span. Though the plumes are visible, most of the worm is anchored in its burrow that it bores into live calcareous coral. Christmas tree worms are very sensitive to disturbances and will rapidly retract into the burrow at the slightest touch or passing shadow.