Soon the new year, so this note will be devoted to one animal, which is entirely I associate with this holiday. What you see in front of him is not just another beautiful underwater plant as a Christmas tree, but a real animal - a tubular marine polychaete worm family Sabellidae.
Tubular marine polychaete worm or worm "Christmas Tree" (Latin Spirobranchus giganteus) (born Christmas tree worm)
You can find it in shallow water among the coral in crystal clear water that is poor in nutrients. Worms are common in the tropical Indian and western Pacific Oceans.
This is a small worm that lives in calcareous tube. Its main building materials are calcium ions and carbonate ions, which removes the worm from the water. Their link is an organic component, isolated from two glands located in the mouth. During the growth of new pipes are added in small rings that are placed at the end of the old tube.
But before you start to build their shelter, the larva worm carefully chooses corals for your house. It suitable only weakened or dead polyps, because they are more convenient to build their own houses-tube.
There are whole colonies of these worms
That so looks like a Christmas tree, a gill-rays, which diverge in 2 separate spiral. They are both respiratory and food (cling of water small particles of organic matter).
Their color may be very diverse: the bright blue, red and yellow, with shades ranging from white to pink and blue and even black, etc. May be that the gill-rays from a worm have a different color.
Another striking feature of these worms is the presence of the tube caps, which tightly buries the entrance to the tube. At the slightest danger of the worm immediately drawn into their spiral gill rays inside the tube, and closes the top lid.