Creature Feature: Tube Worms

A forest of multicolored Christmas-tree worms

Fan worms on a coral head

Marine worms are abundant on reefs, and I thought it apropos to the holiday season to feature the worm above: the Christmas-tree worm. All the worms pictured here are segmented worms, called polychaetes (Latin for “having much hair” because the worms have bristles). The body of the worm is tucked down into a tube that they build on the surface of a rock or burrow right into a coral head, though sometimes the tubes stick up above the substrate like long stalks. But what catches your eye when you’re swimming by are the beautiful arrays of feeding tentacles. These tentacles stick out of the tube to catch food particles in the water. This is called filter feeding. You see here a variety of feeding tentacles, from the single layer in the fanworm, to the fantastically fluffy-looking in the feather-duster worm, and the colorful spirals of the Christmas tree worm. They’re like little flowers blooming on the reef, except that no flower does such a spectacular disappearing act; when you approach too close, the tentacles disappear into the worm’s tube in the blink of an eye.

Feather-duster worms

Close-up of the feeding tentacles