Polycirrus octosetus ( Hutchings, 1977 )

Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), Zootaxa 3877 (1), pp. 1-117 : 83

Polycirrus octosetus ( Hutchings, 1977)

Fig. 45a–g

Litancyra octoseta Hutchings, 1977: 10 , fig. 4a–d.

Polycirrus octoseta Hutchings & Glasby, 1986: 339 , figs 8g –l; 12D.

Type locality. Moreton Bay , Queensland, Australia .

Material examined. HOLOTYPE: AM W6852 , Australia, Queensland, Moreton Bay, Serpentine Creek , 27°24ʹ S, 153°7ʹ E.

Description. Holotype complete, 9 mm long, 1 mm wide at anterior end with 48 segments.

Dorsum anteriorly tessellated (faintly, as reported in paratype). Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads weakly incised, tessellated, extending from segment 3 to 8. Mid-ventral groove from segment 3 poorly defined.

Buccal tentacles numerous, of one type, varying in length, cylindrical, uniformly thin and weakly grooved, arising at junction between prostomium and upper lip. Prostomial ridge distinctly curved, extending laterally along anterodorsal base of upper lip. Upper lip comprising very long single (medial)lobe only, margin of lobe straight; oral surface glandular and ciliated. Inner lower lip oblong; outer region flat, shield-like, oblong, wider than long, smooth, extending posteriorly to segment 3. Achaetous segments visible dorsally but obscured by expanded outer lower lip ventrally ( Fig. 45a ).

Notochaetigerous segments 8, extending to segment 10. Notopodia digitiform, short, lobes both similar, low and rounded. Notochaetae within a chaetiger consisting of two types, smooth, narrowly winged (striations visible under oil), subdistally expanded, posteriorly same form as those anteriorly; secondary notochaetae in all chaetigers smooth, narrowly winged (though striations visible under oil), uniformly tapered ( Fig. 45b–d ). Neurochaetae beginning on segment 17, 32–38 uncini per row. Neuropodial tori erect pinnules, similar along body. Uncini with long neck and concave base (Type 2), teeth above main fang arranged in multiple series of three or four rows (MF:1–3:1–3:2:1) subrostral process absent ( Fig. 45e–g ).

Nephridial papillae not visible in holotype, although specimen is gravid.

Comments. Hutchings & Glasby (1986) reported that eight or nine notochaetigerous segments were present among all the material examined.

Figures

FIGURE 45. Polycirrus octosetus (Hutchings). a. Ventro-lateral view of anterior end. b. Winged type notochaeta. c. Wingless type notochaeta. d. Winged type notochaeta. e. Fronto-lateral view of uncini in situ showing tendons (details of dental formula omitted). f. Lateral view of uncinus from mid-posterior body. g. Frontal views from uncinus from mid-posterior body. Scales e, a, f, c, g, d=0.01 mm, b=0.03 mm. (Reproduced with permission from Hutchings, 1977 http://www.australianmuseum.net.au/ Uploads/Journals/ and Hutchings & Glasby, 1986 http://www.australianmuseum.net.au/Uploads/Journals/17666/185_complete.pdf)