Tangled tubeworms are serpulid worms which form colonies of long, very narrow, white calcareous tubes which together give the impression of fine lace. Each worm is only 1.5 to 4 millimetres long and has a translucent, pinkish-grey body with 30 chaetae down the length of the body. The head bears two eyes and eight tentacles varying in colour from bright red to white emerging from the top, when the worm is not feeding the tentacles are withdrawn into the tube and a protective operculum covers the opening. Tangled tubeworms are filter-feeders, extending their tentacles in to the water current to capture plankton. It forms a thin white tube marked by growth rings. They are a gregarious species that reproduce asexually by budding and sexually by expelling sperm and eggs into the water column during July, August and September.
They occur by encrusting bryozoans and corals and a variety of hard substrata including rock crevices, shells, and sand on the lower shore and sublittoral zone to 25 metres depth. Tangled tubeworms are common around the southern coast of WA to NSW and around Tasmania, they are also common overseas. Other common names include: Coral worm.
Occurrence from the Busselton Jetty:
Varying sizes of colonies of tangled tubeworms can be observed from the underwater observatory, and are often integrated in to the masses of colourful invertebrates adorning the jetty piles. Their appearance changes dramatically when they are feeding and the bright red mass of tentacles are visible.