Key to Australian Freshwater and Terrestrial Invertebrates

Phylum Annelida
Class Polychaeta
Family Sabellidae

Common names: fan worms, feather-duster worms, peacock worms

Overview

Sabellids are recognised by the tentacular crown around their heads made up of radioles, heavily ciliated feather-like tentacles. As well as being used for feeding, this crown is also involved with respiration and some species have sensitive eyespots on the radioles. The animals are generally sedentary, living inside tubes built from organic particles, sand, shells and debris.

Distribution and diversity

There are over 350 sabellid species described worldwide, with over 30 species from 13 genera found in Australian waters. However, most of these are only found in marine habitats. There is only one freshwater species described from Australia; Manayunkia athalassia, from the ephemeral salt lakes near the Coorong region in South Australia. Two other undescribed species from the same genus are also known from the Coorong and from the Pilbara region in Western Australia.

Life cycle

The Sabellidae have a free-living larval form that disperses from the parental site before maturing into an adult form.

Feeding

Sabellids trap suspended particles in the water using their tentacular crown, or feed off of the layer of organic matter deposited on rocks and sediments. As well as being food, these particles are also used for tube building.

Ecology

Sabellids can be solitary or occur in dense aggregations, and occur in both soft sediments and on hard substrates and coral reefs from intertidal to deep oceans. Some, such as the genus Caobangia, are symbiotic in freshwater molluscs.

Manayunkia athalassia

Image credit: Modified from Hutchings, P., De Deckker, P. & Geddes, M.C. (1981)
A New Species of Manayunkia (Polychaeta) from ephemeral lakes near the Coorong, South Australia.
Transactions of the Royal Society South Australia 105(1) 25-28

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