Polycirrus coccineus Grube, 1870

Glasby, Christopher J. & Hutchings, Pat, 2014, Revision of the taxonomy of Polycirrus Grube, 1850 (Annelida: Terebellida: Polycirridae), Zootaxa 3877 (1), pp. 1-117 : 40-41

Polycirrus coccineus Grube, 1870

Fig. 17a–e

Polycirrus (Leucariste) coccineus Grube, 1870: 515–516 .

Type locality. Red Sea.

Material examined. HOLOTYPE: ZMB 529 , Red Sea (no further details) .

Description. Holotype well preserved with body wall and many chaetae damaged, golden yellow in colour; body comprising three fragments which probably originally were connected, anterior fragment 3 mm long and 1.0 mm wide for seven segments excluding buccal tentacles, middle fragment 10 mm long and 1 mm wide for about 70 segments, and posterior fragment 4 mm long and 0.8 mm wide for about 30 segments. Sex unknown.

Dorsum anteriorly tessellated. Venter anteriorly with mid-ventral groove and discrete ventro-lateral pads; pads tessellated, extending posteriorly from segment 4. Mid-ventral groove from segment 3 ( Fig. 17a ).

Buccal tentacles of two types with most tentacles detached from body: (1) cylindrical, thickened distally, distinctly grooved and (2) cylindrical, uniformly thin, weakly grooved, both arising dorsally on prostomial ridge. Prostomial ridge slightly curved, extending laterally along anterodorsal base of upper lip. Upper lip trefoiled with lateral blindly ending enclosed diverticulae, margin of medial lobe convoluted; oral surface glandular, ciliated, with grooves leading to mouth. Inner lower lip oblong, smooth; outer region flat, shield-like, subtriangular and pointing toward mouth, ridged and grooved, extending posteriorly to segment 2. Achaetous segments visible dorsally but obscured by expanded outer lower lip ventrally ( Fig. 17a ).

Notochaetigerous segments 20, extending to segment 22 (approximately). Notopodia digitiform, prechaetal lobe low, postchaetal lobe longer than prechaetal ( Fig. 17b ). Notochaetae consisting of one type (chaetigers 2, 16 examined), gradually elongating from dorsal to ventral, pinnate, similar along body ( Fig. 17c ). Neurochaetae beginning on segment 20. Neuropodial tori erect pinnules, similar along body. Uncini with long neck and concave base (Type 2), teeth above main fang arranged in double transverse series (MF:1:7–8) enlarged median tooth above main fang present (sometimes two enlarged teeth), subrostral process absent ( Fig. 17d, e ).

Nephridial papillae present, globular (flattened). Pre-gular membrane nephridial papillae present on segments 3–4. Post-gular membrane nephridial papillae present, extending from segment 5 to 9; situated at base of notopodia. Pygidium simple rosette.

Comments. Hartman’s (1959) view that Anisocirrus decipiens Gravier, 1905 is a junior synonym of P. coccineus is incorrect because the two species have different uncini: A. decipiens has Type 1 uncini with teeth arranged in a single vertical series, whereas P. coccineus has Type 2 uncini arranged in a double transverse series.

Figures

FIGURE 17. Polycirrus coccineus Grube. Holotype ZMB 529. a. Anterior ventral view. b. Left side posterior lateral view of notopodium, chaetiger 2. c. Notochaeta illustrated at x40 and x100 from chaetiger 16. d. Frontal views of uncini from chaetiger 20. e. Lateral and frontal views of uncini from posterior chaetiger.