Many species! Cirratulids vary in size from one to twenty centimetres long.The head is conical or wedge-shaped and has no antennae. The body is generally cylindrical, tapering at both ends. Cirratulids are characterised by a large number of simple elongate filaments along the body. Some of these occur as an anterior cluster of tentacles, grooved for deposit-feeding, but the majority, the branchiae, are found one pair per segment, and do not have grooves. When alive, the body, branchiae and tentacular filaments are often red, orange or yellow.

They are mostly burrowers in soft sediments but some live in rock crevices. The worm is usually buried with only the writhing branchial filaments visible.

Most are deposit feeders, but some graze on algae or are suspension feeders.

Blake, J.A. (1996). Family Cirratulidae Ryckholdt, 1851. pp. 263-384 in Blake, J.A., Hilbig, B. & Scott, P.H. (eds) The Annelida. Part 3 Polychaeta: Orbiniidae to Cossuridae. Vol. 6. Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and western Santa Barbara Channel. Santa Barbara Museum of Natural History : Santa Barbara, California