Polycirrus multus Hutchings, 1990

Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), Zootaxa 3877 (1), pp. 1-117 : 75-78

Polycirrus multus Hutchings, 1990

Fig. 41a–d , Table 1

Polycirrus multus Hutchings, 1990: 383–384 , Fig. 2a–d .

Material examined. HOLOTYPE: AM W201892 , Tidal Pole Point , Hoi Ha, Hong Kong, 22°27'45.63" N 114°19'47.82" E, part of crevice fauna amongst live coral in shallow water.

Description. Holotype complete, 12 mm long, 1 mm wide, about 85 segments.

Dorsum anteriorly papillose. Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads incised, tessellated, extending from segment 2 to 10. Mid-ventral groove very deep, from segment 3 ( Fig. 41a ). Sex unknown.

Buccal tentacles numerous, of three types: (1) leaf-shaped, deeply furrowed, (2) cylindrical, thickened distally and distinctly grooved, and (3) cylindrical, uniformly thin and weakly grooved, all arising at junction between prostomium and upper lip. Prostomial ridge distinctly curved, extending laterally along anterodorsal base of upper lip. Upper lip with 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, ridged; outer region flat, shieldlike, oblong, wider than long, ridged and grooved, extending posteriorly to segment 3. Achaetous segments visible dorsally but obscured by expanded outer lower lip ventrally ( Fig. 41a ).

Notochaetigerous segments 30, extending to segment 32. Notopodia digitiform, becoming progressively smaller posteriorly, prechaetal lobe low, postchaetal lobe digitiform, slightly longer than prechaetal ( Fig. 41a ). Notochaetae within a chaetiger consisting of one type (chaetigers 4, 12 examined), two distinct lengths, weakly pinnate, posteriorly same form as those anteriorly ( Fig. 41b ). Neurochaetae beginning on segment 14. Neuropodial tori erect pinnules, rectangular initially, becoming wedge-shaped then globular more posteriorly ( Fig. 41d ). Uncini with short neck and straight to convex base (Type 1), teeth above main fang arranged in single transverse series ( MF:8–∞) (see Comments), subrostral process present as low protuberance ( Fig. 41c ) .

Nephridial papillae present, cylindrical, small. Pre-gular membrane nephridial papillae present on segments 3–4. Post-gular membrane nephridial papillae present extending from segment 5 to 8; situated at ventral base of notopodia. Pygidium simple rosette.

Comments. According to the type description, the uncini have a dental formula of MF:5:3:∞, that is three rows above the main fang. However, Fig. 41c shows only one row of teeth above the main fang. Therefore, using the present dental formula concept (i.e., counting teeth as a series in curved rows; see Table 2) the formula should be MF:8–∞, that is, eight to many teeth arranged in a single curved row above the main fang.

Figures

FIGURE 2. Head of Polycirrus showing major features referred to in the description. a. dorsal view. b. ventral view. Abbreviations as follows: Pr = prostomial ridge, Ul = upper lip, Bt = buccal tentacle, Ul-ll Upper lip lateral lobe, Ul-ml = Upper lip medial lobe, Oll = outer lower lip, Ill- inner lower lip, I, II, III, IV, V = segment number.

FIGURE 41. Polycirrus multus Hutchings. a. Anterior ventral view. b. Notochaeta. c. Uncinus, lateral view. d. Anterior-mid body, ventral view. Scales a, d= 1 mm, b, c= 0.01 mm. (Redrawn from Hutchings, 1990).