Sphaerosyllis rotundipapillata Hartmann-Schröder, 1982

Guillermo San Martin, 2005, Exogoninae (Polychaeta: Syllidae) from Australia With the Description of a New Genus and Twenty-two New Species, Records of the Australian Museum 57, pp. 39-152 : 88

Sphaerosyllis rotundipapillata Hartmann-Schröder, 1982

Fig. 42A–M

Sphaerosyllis rotundipapillata Hartmann-Schröder, 1982: 73 , figs. 60–68; 1983: 135; 1984: 24; 1985: 24; 1991: 72.

Material examined. AUSTRALIA: WESTERN AUSTRALIA. 3 specimens, HZM P-17069, Fremantle, algae, intertidal, G. Hartmann-Schröder, 2 Nov 1975.

Description. Body small, proportionally long and slender, filiform, up to 4.1 mm long, about 0.17–0.2 mm wide, 38 chaetigers. Anterior segments with few, small round papillae ( Fig. 42A ); from about chaetiger 6 and midbody chaetigers, papillae numerous ( Fig. 42B ) covering dorsum, some papillae on parapodia, and ventrum; papillae long, distinct, with slender stalk and expanded, rounded or truncated tips ( Fig. 42B ), with slightly dark inclusions. Papillae absent on prostomium and palps, sparse on peristomium and more anterior and posterior segments. Prostomium trapezoidal; 4 large eyes in trapezoidal arrangement.Antennae relatively long in relation to dorsal cirri, with bulbous bases and long, slender tips, distinctly shorter than prostomium and palps together ( Fig. 42A ). Palps similar in length to prostomium, fused along their length, with distal notch. Peristomium shorter than following segments, covering posterior part of prostomium; tentacular cirri small, distinctly shorter than antennae. Dorsal cirri short, similar to tentacular cirri, shorter than parapodial lobes, with bulbous bases and short tips ( Figs. 42A,B,C ). Parapodial lobes rectangular in dorsal view, provided with 2 distal, rounded papillae ( Fig. 42A ). Ventral cirri relatively long, slender. Parapodial glands small, difficult to see, with granular material ( Fig. 42A,B ). Anterior parapodia each with 7 compound chaetae with unidentate blades; shafts more angular and thicker ventrally, with a subdistal small spur ( Fig. 42E ); blades of dorsal compound chaetae with long, straight marginal spines, about 9–10 µm long, blades of ventral compound chaetae smooth, similar in length to dorsal blades. Number of compound chaetae on each parapodium diminishing posteriorly to 3 on midbody ( Fig. 42H ) and posterior parapodia ( Fig. 42L ), with thick shafts provided with strong subdistal spur giving bifurcate appearance, and hooked blades, smooth or provided with short marginal spines, similar in length to those on anterior and midbody compound chaetae. Dorsal simple chaeta from anterior parapodia, usually from chaetiger 1, unidentate, with a distinct subdistal spur, provided with small superior spines ( Fig. 42G,K ), slender on anterior parapodia ( Fig. 42D ).Ventral simple chaetae present on posterior parapodia, sigmoid, distally hooked, unidentate, smooth ( Fig. 42M ). Most anterior parapodia each with one slender, straight acicula and another one bent at tip, forming right angle ( Fig. 42F ); solitary acicula with bent tip, at right angle in remaining parapodia ( Fig. 42I,J ). Pygidium small, with some rounded papillae and two anal cirri, similar to dorsal cirri but much longer ( Fig. 42C ). Pharynx through 3–4 segments; pharyngeal tooth relatively long, conical, on anterior rim ( Fig. 42A ). Proventricle through 2–3 segments, with 14–18 muscle cell rows.

Distribution. Australia (Western Australia, South Australia and questionably Queensland [Hartmann-Schröder, 1991]).

Habitat. Sand, amongst algae, Posidonia beds. Intertidal and shallow bottoms.

Figures

Fig. 42. Sphaerosyllis rotundipapillata. (A) anterior end, dorsal view. (B) midbody segment, dorsal view. (C) posterior end, dorsal view. (D) dorsal simple chaeta, anterior parapodium. (E) compound chaetae, anterior parapodium. (F) aciculae, anterior parapodium. (G) dorsal simple chaeta, midbody. (H) compound chaetae, midbody. (I) acicula, midbody. (J) acicula, posterior parapodium. (K) dorsal simple chaeta, posterior parapodium. (L) compound chaetae, posterior parapodium. (M) ventral simple chaeta. Scale A–C: 0.9 mm, D–M: 20 µm.