The holopelagic polychaete Poeobius meseres, which is up to 27 mm in length and has 11 poorly defined segments, is the sole recognized representative of Poeobiidae (Annelida; Fig.
Relationships within this putative clade (also including Acrocirridae, Cirratulidae, Ctenodrilidae, Fauveliopsidae, Poeobiidae, and Sternaspidae) remain unclear.
With the recognition of Poeobiidae Heath 1930, the monophyly of Flabelligeridae has been called into question.
This action makes "Poeobiidae" (Heath, 1930) a junior synonym of Flabelligeridae Saint-Joseph, 1894.
Five phyllodocidacean families (Alciopidae, Lopadorrhynchidae, Pontodoridae, Tomopteridae, and Typhloscolecidae) and two flabelligerid families (Flotidae and Poeobiidae
) are dominated by transparent species (Uschakov, 1972; Glasby et al., 2000).