Christmas Tree Worm

Care at a glance

Overview

The worms need a mature tank of 75 litres or more at 24 to 27 C and pH 8.1 to 8.4, but the real challenge is keeping the host coral alive. That means strong light and flow for the Porites plus regular fine plankton feeding for the filter feeding worms. They are reef safe and harmless, but if the host coral dies the worms usually follow, so they suit established reefs only.

In the wild

Each christmas tree worm shows two bright spiral crowns that stick up out of a living coral head like little fir trees. The crowns come in red, orange, blue, white, and yellow and pull instantly into a hidden tube when a shadow passes. They are almost always sold as a piece of Porites coral studded with many worms.

Good to know

Spirobranchus giganteus builds a hard calcium tube inside a living coral, most often Porites, and the two grow together over years. The spiral crown works as both its gill and its feeding fan, straining plankton from the water.

Did you know

The worm and its host coral live together for years, with the coral slowly growing up around the worm's tube.

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