Can a worm help save a coral reef? Yes and that is exactly what kio the Christmastree worm does. Kio is only three inches long and it makes a ridged calcium carbonate tube right into a live coral. When the worm has its spiral fans out of its tube it looks like two Christmas trees side by side. The circular fan-like structures filter zooplankton from the sea water and these fans come in many colors from blue, yellow, red to white. At any given time the fans can retract back into the tube that buried deep into the live coral. Kio even has a trap door with spikes on top to protect the worm in its tube.