Christmas tree worms, Spirobranchus giganteus, are usually found in coral reefs in tropical waters. According to various google sources the colourful plumes are used for passive feeding on suspended food particles and plankton in the water. The plumes are also used for respiration.
They anchor themselves with a tubular burrow bored into live hard corals. Though the plumes are visible, most of the worm is inside its burrow and are very sensitive to disturbances, rapidly retracting into the safety of the burrow at the slightest passing shadow. They typically re-emerge a minute or so later, very slowly, to test the water before fully extending their plumes.
The Christmas tree worm are polychaete ciliary feeders that feed using their radioles, the hair-like appendages that circle outward from the central spine, to catch phytoplankton floating in the water column. The food is then passed down the food groove by the feeding pinnules (ciliary tracts or tiny hair-like extensions on the surface of cells that generate water currents to move food or mucus). The food particles are sorted and larger particles are discarded. Sand grains are directed to storage sacs to be used later for tube building.
References & further reading… http://marinebio.org , http://en.wikipedia.org/wiki/Spirobranchus_giganteus
Ok, the thought of a worm is not all that appealing but hey, they are really cute and come in all different colours! I’ve decided to devote a gallery to them on my photo site! http://www.pbase.com/suzy_walker/xmas_tree_worms
Some are more in focus than others – I was using a 60mm macro lens, would have been better with a 105! All shot with a Nikon D300. Click the images to see lager versions. They are all from our recent trip with Mark Webster to Hurghada & the Brothers with Oonas divers. The photos from the rest of the trip will hopefully be processed and uploaded shortly :)