Cirratulids are deposit-feeding worms that burrow or crawl through the substratum. Australian cirratulids live in bays and estuaries in a range of sediment types, often associated with seagrass beds (except Dodecaceria which bores into calcareous substrates). In organically enriched sediment in estuaries they can reach high population densities. They typically bury their bodies just below the surface with their long branchiae and tentacles visible at the surface.
Diversity
Despite recent studies by Blake (1991 & 1996) this family is in need of a comprehensive systematic revision, with many potential new species and genera, and likely synonymies of existing genera. The number of species worldwide and in Australia cannot be estimated accurately in the absence of a taxonomic revision. In recent years several genera have been removed to other families (Ctenodrilidae, Cossuridae and Acrocirridae). The on-going work of Blake and of Petersen support the theory that high numbers of endemic species of cirratulids are to be expected, and that widely distributed and cosmopolitan species are probably rare.
All known Australian species included - 17, representing 8 genera - are based on published descriptions, and another 13 species from 4 genera are provisionally identified from major benthic surveys of soft sediments in southeastern Australia. The principal areas surveyed are Bass Strait and Port Phillip Bay (material held in Museum Victoria, Melbourne) and Jervis and Botany Bays (material held in Australian Museum, Sydney). Many taxa undoubtedly remain to be described from Australian waters, especially beyond the soft sediment communities of southeastern Australia which have generated much of the material covered here.
