Sabellids build tubes out of a tough, parchment-like exudate, strengthened with sand and bits of shell.

[1][2] Feather-duster worms have a crown of feeding appendages or radioles in two fan-shaped clusters projecting from their tubes when under water.

Each radiole has paired side branches making a two-edged comb for filter feeding.

The usually eight thoracic segments bear capillaries dorsally and hooked chaetae (bristles) ventrally.

Some small species can bend over and extend their tentacles to the sea floor to collect detritus.