Tuesday, 2 June 2009
The Christmas Tree Worm
This unusual submarine dweller is the aptly-named Christmas Tree worm.
The Christmas tree worm (spirobranchus giganteus) is a Christmas tree-shaped tube-dwelling worm with magnificent twin spirals of plumes used for feeding and respiration.
These cone-shaped worms come in many colours including orange, yellow, blue, and white and, though they are small, with an average span of less than 4cm, they are easily spotted due to their shape, beauty, and striking hues.
The colourful plumes - or tentacles - are used for passive feeding, the worm living off suspended food particles and plankton floating by in the water. The plumes are also used for respiration. Though the plumes are visible, most of the worm is anchored in its burrow that it bores into a live coral.
Christmas tree worms are very sensitive to disturbances and will rapidly retract into their burrows at the slightest touch or even a passing shadow. They typically re-emerge a minute later, very slowly, to test the water before fully extending their plumes.
And they really do look just like Christmas trees...