Christmas Tree Worms Stay Spirited All Year

Families that celebrate Christmas will likely have a colorful tree lighting up their living room right now. But under the sea, millions of Christmas tree worms remain festive all year. Christmas tree worms, whose scientific name is Spirobranchus giganteus, have two spiraled crowns on their back that each resemble a tiny colorful Christmas tree.

These “trees” can be a single solid color but are also often multi-toned, with a second color gracing the outer tips of their spirals like garland. And these worms don’t restrict themselves to red and green. Some are a brilliant blue or bright yellow, while others might be white with orange tips, ruby with white tips, gold with maroon and white tips or any number of other combinations.

These colorful spirals help the worm breathe and catch food. The worms anchor themselves to coral and use the feather-like tentacles protruding from their spirals to catch tiny prey from the surrounding water and move it to the worm’s mouth. If the worm is startled, it retreats into burrows in the coral to hide from possible predators.

Over time, these burrows in the coral can reach 10 inches in length, providing a roomy hiding place for a critter that lives up to 30 years. These worms also help coral recover more quickly from bleaching events and protect it from predators. In fact, in perhaps a bit of an ironic twist, scientists have seen Christmas tree worms literally push away the feet of predatory crown of thorns starfish.