Christmas Tree Worm

These beautiful spiral rings are actually the gills and mouth of a little marine worm that makes it home in a borrow formed in a hard coral reef.  Each ring is about the size of a quarter and each worm has a double set.  They can withdraw down their tube in the blink of an eye if they're disturbed.  Just a shadow passing over them is enough for them to disappear.  From a side view they have a conical shape like a Christmas Tree and they come in a great variety of colors.  They're also called Tube Worms after the shape of their homes.  I photographed this worm in a large brain coral.