Polydora aura Sato-Okoshi, 1998

Prostomium blunt, anteriorly truncate or rounded, anterior margin bifid, with anterior margin indented (weakly). Lateral horns absent. Caruncle present, continuing back to chaetiger 2–3, fused with dorsum. Occipital antenna present. Nuchal organ short, at most one segment long. Eyes present, or absent; 1–4 eyes. Palps simple, lacking basal sheath. Body and palps light orange, transparent in life. Dorsal ridge connecting bases of branchiae on chaetiger 1 absent. Prominent dorsal collar on setiger 2 absent. Dorsal branchiae present, first present on chaetiger 7. Dorsal branchiae continue to near posterior end of body. Dorsal branchiae continuous. Dorsal branchiae free and separate from notopodial lamellae throughout, all simple. First branchiae without process at base on anterior face. Accessory branchiae arising from posterior part of notopodium absent. Ventral branchiae absent. Chaetiger 3 without filament at base of branchiae. Dorsal crests absent. Ventral crests absent. Chaetiger 1 notopodium present. Chaetiger 1 notochaetae absent. Neuropodial lobe of chaetiger 2 rounded, approximately symmetrical. Neuropodial lobes of posterior chaetigers a single lobe. Interparapodial pouches absent. Chaetigers 2–4 similar, not strongly differentiated. Chaetiger 5 highly modified, enlarged and with specialised chaetae, with one type of modified spine present; 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 absent; companion chaetae present; companion chaetae limbate; companion chaetae not brush-tipped. Posterior modified notochaetae present. Notopodial hooded hooks absent. Neurochaetae of chaetiger 1 simple capillaries similar to those of subsequent chaetigers. Neuropodial hooded hooks present, first present on chaetiger 7. Neuropodial hooded hooks with accessory tooth or teeth above the main fang, 1 accessory tooth (bidentate), secondary tooth closely applied to the main fang, about 45º. Shaft of neuropodial hooded hooks with distinct constriction. Neuropodial sabre chaetae absent. Neuropodial spines absent. Embedded bunches of notopodial needle chaetae present in posterior chaetigers. Pygidium a wide flaring disk.

Description generated from: Wilson, RS & McDiarmid, H 2013. Spionidae (Polychaeta)- A DELTA database of genera, and Australian species. Version 2; originally published as In RS Wilson, PA Hutchings & CJ Glasby (eds) Polychaetes: An Interactive Identification Guide. CSIRO Publishing, Melbourne.

Additional references:
Sato-Okoshi, W. 1998. Three new species of polydorids (Polychaeta, Spionidae) from Japan. Species Diversity 3: 277-288.
Sato-Okoshi, W., Okoshi, K., and Shaw, J. 2008. Polydorid species (Polychaeta: Spionidae) in south-western Australian waters with special reference to Polydora uncinata and Boccardia knoxi. Journal of the Marine Biological Association of the UK 88: 491-501.