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Poeobiidae
Description
The prostomium is truncate and retractable.
The peristomium is assumed to be reduced, but Rouse &
Pleijel (2001) suggest that there is no evidence to support
this concept. There are no antennae. The paired, grooved
peristomial palps are located dorso-laterally to the mouth.
Nuchal organs are present. The arrangement of longitudinal
muscles is unknown; segmentation is indistinct, and two septa
divide the body into three coelomic pockets.
All parapodial structures are lacking. Five to seven pairs of
eversible branchiae occur at the anterior end;
these branchiae appear similar to those present in
flabelligerids. Epidermal papillae of the
flabelligerid type are present. A ventral, eversible buccal
organ is present and the gut is folded. A gular membrane is
apparently present. Lateral organs and dorsal cirrus organs
have not been observed. The excretory organs are
metanephridia, and the segmental organs are possibly mixonephridia.
A single pair of nephridia is present anteriorly;
opening in front of the branchiae. A pair of
gonoducts is present. The circulatory system is closed and a
heart body is present. No chaetae, or aciculae, are present.
The above definition is taken from Hutchings (2000), which is based on that of Fauchald & Rouse (1997).
Identification tips
Recognising the family
The Poeobiidae is a monotypic family of pelagic polychaetes with a sac-like gelatinous body, lacking external segmentation or chaetae and with a
circlet of eversible branchiae on the head.
Description |
Identification tips |
Natural History |
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References |
Identification guide
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