Comprehensive Description

Read full entry

Description

Prostomium blunt, anteriorly truncate or rounded, anterior margin bifid, with anterior margin indented. Lateral horns absent. Caruncle present, continuing back to chaetiger 3–4. Occipital antenna present. Nuchal organ short, at most one segment long or long, extending back more than one segment. Eyes present. Palps simple, lacking basal sheath. Dorsal ridge connecting bases of branchiae on chaetiger 1 absent. Prominent dorsal collar on setiger 2 absent. Dorsal branchiae present, first present on chaetiger 10. Dorsal branchiae absent from many median and posterior chaetigers, last present on chaetiger 22–28. 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 present, or absent; spines with subdistal tooth or flange present, or absent; 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 brush-tipped. Posterior modified notochaetae absent. 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 and main fang forming a prominent angle, about 90º or more. Shaft of neuropodial hooded hooks with distinct constriction. Neuropodial sabre chaetae absent. Neuropodial spines absent. Embedded bunches of notopodial needle chaetae absent.

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.

Trusted

Creative Commons Attribution 3.0 (CC BY 3.0)

© Wilson, Robin

Source: Annelida LifeDesk

Belongs to 1 community

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!