Marine Animal Encyclopedia
Honeycomb Worm Sabellaria alveolata
Although honeycomb worms are tiny, the sand tubes they build may cover many yards of rock in rounded hummocks up to 20 in (50 cm) thick. Honeycomb worms build their tubes close together, and the tube openings give the colony a honeycomb appearance. This worm’s head is crowned by spines and it has numerous feathery feeding tentacles around the mouth, which it uses to trap plankton. The honeycomb worm's body ends in a thin, tubelike tail with no appendages.
Honeycomb Worm Reefs
Honeycomb worms build their tubes by gluing together sand grains stirred up by waves. The glue is a mucus secreted by the worm, which uses a lobed lip around its mouth to fashion the tube. As new honeycomb worms settle out from the plankton to build their own tubes, a reef develops and expands sideways and upward, provided there is a good supply of sand. These structures provide a home to many other species.