Polycirrus tesselatus Hutchings & Glasby, 1986

Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), Zootaxa 3877 (1), pp. 1-117 : 104-106

Polycirrus tesselatus Hutchings & Glasby, 1986

Fig. 59a–g , Table 1

Polycirrus tesselatus Hutchings & Glasby, 1986: 343–345 , figs 10f–l; 12E.

Type locality. Western Port , Victoria, Australia .

Material examined. HOLOTYPE: MV F503337 , Australia, Western Port Bay , 38˚26′ S, 145˚08′ E. coll. 20.xi.1973.

Description. Holotype incomplete, 8 mm long, 2 mm wide.

Dorsum anteriorly tessellated ( Fig. 59a ). Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads incised (tessellated), extending from segment 3 to 12 (to segment 15 in paratypes), posterior ones small and poorly defined. Mid-ventral groove from segment 5 but not well defined until about segment 10 ( Fig. 59b ).

Buccal tentacles variable, long, numerous, of one or two types: (1) 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 prominent medial lobe, small wing-like lateral lobes, margin of medial lobe convoluted; oral surface glandular, ciliated, with grooves leading to mouth. Inner lower lip oblong, narrow, ridged; outer region flat, shield-like, oblong, wider than long, almost semi-circular, ridged and grooved, extending posteriorly to segment 3. Achaetous segments visible dorsally, both equal in length to segment 2, but obscured by expanded outer lower lip ventrally ( Fig. 59a, b ).

Notochaetigerous segments 10, extending to segment 12. Notopodia more-or-less rectangular, lobes triangular, postchaetal lobe slightly longer than prechaetal ( Fig. 59c ). Notochaetae within a chaetiger consisting of one type, gradually elongating from dorsal to ventral, smooth, narrowly winged although worn ones appear hirsute near tip, uniformly tapered, posteriorly same form as those anteriorly ( Fig. 59d,e ). Neurochaetae beginning on segment 15, 22–40 uncini per row. Neuropodial tori erect pinnules directed posteriorly; initially minute, then increasing in size posteriorly, differ along body. Uncini with short neck and straight to convex base (Type 1), teeth above main fang arranged in multiple series (MF:1:6–12) enlarged median tooth above main fang present, subrostral process present as low protuberance ( Fig. 59f, g ).

Nephridial papillae present, globular. Pre-gular membrane nephridial papillae absent. Post-gular membrane nephridial papillae present, extending from segment 5 to 10; situated at posteroventral base of notopodia.

Comments. Hutchings & Glasby (1986) report the following variation in the paratypes: 10–16 notochaetigerous segments, neurochaetae from segment 10–16, and dental formula of uncini MF:1–5:5–17:∞ ( Table 1 ).

Figures

FIGURE 59. Polycirrus tesselatus Hutchings & Glasby. a. Ventral view of head end. b. Dorsal view of head end. c. anterior view of notopodius 5. d,e. Notochaeta from notopodius 5. f. Lateral views of uncini from mid-posterior body. g. Frontal view of uncini from mid-posterior body. Scales c=0.03 mm, d, e, f=0.01 mm, a=2 mm. Reproduced with permission from Hutchings & Glasby, 1986; http://www.australianmuseum.net.au/Uploads/Journals/17666/185_complete.pdf.