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Spionid worm

Scientific Name
Dipolydora armata
Scientific Author
Langerhans, 1881
Annelida: Polychaeta: Spionidae
Australian Native Species

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Diagnostic Images

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Diagnostic Images (4)
Other Images (1)
Diagnostic Notes

Prostomium blunt, Anteriorly truncate or rounded; bifid, with anterior margin indented; without frontal or lateral horns. Posterior prolongation of prostomium continuing back to chaetiger 2 (posterior margin). Occipital antenna absent. Nuchal organ short, at most one segment long, or long, extending back more than one segment. Eyes absent. Palps simple, lacking basal sheath.

Dorsal branchiae present, first on chaetiger 7 (reaching maximum size by chaetiger 8), absent from many median and posterior chaetigers, last present on 11-12. Dorsal branchiae continuous. Dorsal branchiae free and separate from notopodial lamellae throughout, all simple. Accessory branchiae arising from posterior part of notopodium absent. Ventral branchiae absent.

Dorsal crests absent. Chaetiger 1 with notochaetae (2-3 notochaetae only).

Chaetigers 2-4 similar, not strongly differentiated. Chaetiger 5 highly modified, enlarged and with specialised chaetae; with one type of modified spine present. Chaetiger 5: simple, curved or subdistally inflated spines absent; spines with subdistal tooth or flange present; pennoned spines, with strongly asymmetrical tips absent; spines with flattened or cup-shaped tip absent; spines with terminal or subterminal bristles present. Chaetiger 5 companion chaetae absent. Posterior modified notochaetae absent, on chaetiger posterior chaetigers; usually not emergent in small specimens. Notopodial hooded hooks present. Neurochaetae of chaetiger 1 simple capillaries similar to those of subsequent chaetigers. Neuropodial hooded hooks absent; first on chaetiger 7; with accessory tooth or teeth above the main fang; with 1 accessory tooth (bidentate); secondary tooth closely applied to the main fang, about 45º (about 50º). Shaft of neuropodial hooded hooks of constant thickness, lacking a constriction. Neuropodial sabre chaetae present, in ventral-most positions. Neuropodial spines present. Pygidium small, cuff-shaped, with dorsal and ventral gaps.

More Information
Specimen Contact
Robin Wilson
Wilson, R. & Dane, E.
12/06/2008 02:56 AEST
Last Updated
12/04/2011 15:15 AEST
Wilson, R. & Dane, E. (2008) Spionid worm (Dipolydora armata) Updated on 4/12/2011 3:15:12 PM Available online: PaDIL -
Image Use
Free for use under the Creative Commons Attribution 3.0 Australia License