Description:-
Body: Widest mid-anteriorly (corresponding to increased muscularisation between setigers 9–20), tapering gradually anteriorly and posteriorly. Dorsum convex. Venter flat with deep medial groove, or convex in one specimen turgid with oocytes. Colour in alcohol yellow-white to yellow-brown. Epidermal pigment absent. Living colour pale pink with subcutaneous green pigment posterodorsally.
Prostomium: Shallowly cleft anteriorly, with narrow longitudinal groove extending from tip to mid-posterior prostomium (often ending in pit or shallow depression). Prostomium shape roughly triangular or trapezoidal (rarely), laterally notched or slightly indented, rarely not notched or indented; 1.5–2.0 × wider than long. Antennae smooth, extending beyond tip of palpophore or short of tip of palpophore, aligned over inner edge of palps to over mid-palps. Eyes 2 pairs, black or red, arranged longitudinally or obliquely, equal in size or posterior pair slightly smaller (eyes absent in some specimens—probably faded); lenses present.
Peristomium. Tentacular cirri with cirrophores distinct; cirrostyles faintly jointed or rarely smooth. Anterodorsal tentacularcirri1. 8 – 2.5 × length anteroventral. Anterodorsal tentacularcirri 0.6 – 0.9 × length posterodorsal. Posterodorsal tentacular cirri 1.7–2.5 × length posteroventral (occasionally to 1.2). Posterodorsal tentacular cirri extending posteriorly to setiger 5–6 (to setiger 3 in small specimens) (Fig. 21a). Jaws with single robust terminal tooth, 2–5 subterminal teeth, 3–5 teeth ensheathed proximally, brown.
Parapodia. Acicular neuropodial ligule subconical or rarely, slightly bilobed (Fig. 21c). Dorsal cirri increasing slightly in length posteriorly; 0.88–1.9 × length of podium at setiger 3, 2.0–4.0 × length of podium in mid-body (occasionally 1.2–5.0), 3.2–6.7 × length of podium posteriorly; 4.1–6.0 × longer than wide posteriorly. Ventral cirri 0.33–0.72 length of podium at setiger 3, 0.50–0.71 length of podium posteriorly.
Setae. Notopodial sesquigomph spinigers from setiger 1–4 (occasionally from setiger 7). Supra-neuroacicular setae include sesquigomph spinigers in postacicular fascicles and heterogomph falcigers in preacicular fascicles Sub-neuroacicular setae include heterogomph spinigers in postacicular fascicles and heterogomph falcigers in preacicular fascicles.
Supra-neuroacicular sesquigomph spinigers in setiger 10 with boss 1.4–1.6 × length of collar. Heterogomph setae with boss not prolonged. Supra neuroacicular falcigers in setiger 10 with blades 5.7–8.9 × longer than width of shaft head, finely serrated, 11–22 teeth, 0.35–0.58 × total blade length, teeth about uniform in length. Sub-neuroacicular falcigers in setiger 10 with blades finely serrated; dorsal-most 6.0–11.3 × longer than width of shaft head, 15–30 teeth; ventral most 5.0–7.5 × longer than width of shaft head, 8–15 teeth. Sub-neuroacicular falcigers in mid-posterior region with blades finely serrated and/or increasingly coarsely serrated proximally; falcigers with proximally coarsely serrated blades from setiger 10–30. Sub-neuroacicular spinigers in anterior region with blades finely serrated; posteriorly, from setiger 3–10, with blades having coarse serrations proximally. Setae pale. Acicula in mid-body black or brown.
Pygidium. Pygidium tripartite with 2 large lateral lobes and smaller pointed dorsal lobe (difficult to see dorsal lobe). Rarely pygidium drawn out into funnel shape. Anus terminal. Anal cirri arising ventrolaterally or laterally, approximately conical or flattened (rarely), smooth, 3.0– 8.0 × width pygidium (occasionally to 1.5).
Sex. Mature oocytes 105 µm (± 5, 1 specimen measured), straw-coloured, with thin external membrane. Epitokal setae in females are slender compound spinigers (unknown in males).
References:-
WoRMS (2014). Namalycastis indica (Southern, 1921). In: Read, G.;
Fauchald, K. (Ed.) (2014) World Polychaeta database. Accessed through:
World Register of Marine Species at http://www.marinespecies.org/aphia.php?
p=taxdetails&id=209756 on 20150122
Glasby, C. J. 1999. The Namanereidinae (Polychaeta: Nereididae).Part 1, Taxonomy and Phylogeny. In: Records of the Australian Museum, Supplement 25