This is one of the most interesting and colorful additions for a reef tank, but also one of the more challenging.
The Christmas Tree Rock is actually two different kinds of animals living together. The base is a living SPS coral (Porites sp.) that grows in a massive or encrusting form. Living in and on this coral is a colony of Christmas Tree Worms (Spirobranchus giganteus).
These worms have colorful plumes in a dazzling variety of colors. One of the fascinating things about these colonies is that they always feature multiple colors, so no two are alike. The worms extend their plumes to filter the water and retract them when a shadow passes over the colony, adding both color and motion to your tank.
Now the downside — these colonies are fairly challenging to keep. The coral requires typical SPS conditions to thrive — high turbulent flow, moderate to high light, and clean water. The worms, on the other hand, require frequent feeding with phytoplankton. Achieving both of these in the same aquarium is the challenge to keeping these specimens. But for those who manage it, the colonies provide an eye-catching centerpiece to the reef.
Like all corals, every specimen is unique. This is especially true for Christmas Tree Rocks. We provide several pictures to illustrate the range of shapes and colors, but the specimen you receive is likely to look different from these images because of the extreme variation among specimens in this group.