Christmas Tree Worm (Spirobranchus corniculatus) イバラカンザシ
The Christmas Tree worm was once known as Spirobranchus giganteus which is now the Atlantic Christmas Tree Worms. The Pacific Christmas Tree Worms were broken up into several species. These are now considered to be one species Spirobranchus corniculatus which is very polymorphic. It favors Porites Lobatal coral as its host.
Blue Christmas Tree Worm (Spirobranchus corniculatus) growing in Porites Lobata
Christmas Tree Worm
Porites Lobata coral head with many Christmas Tree Worms.
Christmas Tree Worm hole with the door just opening and the fan starting to extend. Notice the sharp spine, a tree will open on each side of the spine.
Christmas Tree Worm extended. The door at bottom center with an orange edge.