Family PARAONIDAE

Paraonidae

© Copyright Greg Rouse

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Introduction

Paraonids are elongate, thread-like worms. They have a coiled body and bluntly conical prostomium. They are deposit-feeders and are found from the intertidal to the deep sea, and are especially common in soft sediments.

Figures of 3 genera and 3 species were given by Beesley et al. (2000: App. 1) for representation of the family in Australian waters, and 12 genera and 86 species worldwide. This database includes 6 species from 3 genera.

See Glasby (2000) for detailed treatment of the family.

Database Notes

proof read against Day & Hutchings 1979 by RW; no subsequent records added
checked against DELTA CD, 2003 by RTJ

Diagnosis

General features. Body shape vermiform; segments numerous (more than about 15); regionation absent. Ventral groove absent. Pygidium simple ring or cone. Pygidial appendages present; one pair of cirri, or more than four cirri, or three cirri (typical).
Head & head structures. Head discrete and compact, dorsal to mouth. Prostomium bluntly conical to trapezoidal (narrow end anteriorly); anteriorly without deep incisions, cirri or palpodes, or with a palpode. Eyes absent, or present; one pair; situated on prostomium; without lenses. Prostomial antennae absent, or present; single arising anteromedially (may be absent); smooth. Palps absent. Nuchal organs indistinct paired dorsolateral patches. Peristomial ring absent.
Pharynx & pharyngeal apparatus. Foregut a non-muscular axial proboscis, or a ventral pharyngeal organ; dorsolateral ciliated folds absent, or present.
Body segments & parapodia. First segment chaetigerous. First chaetiger with both notochaetae and neurochaetae. Parapodia biramous with parapodial lobes absent or low; notopodial lobes represented by at least one chaetal lobe; neuropodial lobes represented by at least one chaetal lobe. Lateral organs absent, or present. Dorsal cirri absent. Ventral cirri absent. Branchiae present; arise from dorsum; occur on at least some chaetigerous segments (limited region); digitiform (may be flattened).
Chaetae. Notochaetae present. Aciculae absent. Capillary chaetae hair-like; smooth, or hirsute-serrate. Forked chaetae absent, or present; lyrate type; tines distinctly unequal in length. Spines present in most or all chaetigers; in both notopodia and neuropodia; slightly curved and more-or-less smooth, or with a single distal or subdistal hair (=aristate or hooded). Hooks absent, or present (rarely); with a distal hood; occur in many chaetigers but only one ramus.
Tube & burrow. Tube absent or unconsolidated. Burrow traces horizontal spirals.

The above description was generated from: 'C.J. Glasby & K. Fauchald (2002 onwards). POLiKEY. An information system for polychaete families and higher taxa: Version 1: September 2002.'
(See ABRS website: Online Resources: Polikey, for Version 2, released June 2003)

General References

Beesley, P.L., Ross, G.J.B. & Glasby, C.J. (eds) 2000. Polychaetes & Allies: The Southern Synthesis. Fauna of Australia Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. Melbourne : CSIRO Publishing Vol. 4 Part A xii 1-465 pp.

Fauchald, K. & Rouse, G. 1997. Polychaete systematics: Past and present. Zoologica Scripta 26: 71-138

Glasby, C.J. 2000. Family Paraonidae. pp. 82-84 in Beesley, P.L., Ross, G.J.B. & Glasby, C.J. (eds). Polychaetes & Allies: The Southern Synthesis. Fauna of Australia Vol. 4A Polychaeta, Myzostomida, Pogonophora, Echiura, Sipuncula. Melbourne : CSIRO Publishing Vol. 4 Part A xii 1-465 pp.

History of changes