Sphaerosyllis voluntariorum Martin, 2005, n.sp.
Creators: name: Guillermo San Martin
Publisher: name: Zenodo
Year: 2005
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Phyllodocida
Syllidae
Sphaerosyllis
Sphaerosyllis voluntariorum

description: Sphaerosyllis voluntariorum n.sp.
Fig. 44A–I
Material examined. AUSTRALIA: WESTERN AUSTRALIA. HOLOTYPE: AM W26821, Ningaloo reef off Ned’s Camp, Cape Range National Park, 21°59.5'S 113°54.5'E, mixed algae, 2 m, J.K. Lowry, 1 Jan 1984.
Description. Body small, slender, 1.4 mm long, 0.14 mm wide, 26 chaetigers. Papillae numerous (Figs. 44A,B,C) covering dorsum, few papillae on parapodia; papillae long, distinct, with slender stalk and expanded, rounded or slightly trilobed tips, with dark inclusions. Papillae absent on prostomium and palps. Prostomium ovate to trapezoidal, wider than long; 4 large eyes in trapezoidal arrangement. Antennae relatively long, with bulbous bases and long, slender tips, similar to combined length of prostomium and palps (Fig. 44A). Palps similar in length to prostomium, fused along their length, ventrally folded. Peristomium similar in length to following segments, covering posterior half of prostomium; tentacular cirri shorter than antennae. Dorsal cirri similar to tentacular cirri, similar in length to parapodial lobes, with bulbous bases and slender tips (Fig. 44A,C), elongate on midbody. Parapodial lobes conical, provided with 2 subdistal, rounded papillae (Fig. 44A,C), and sometimes few other basal papillae similar to dorsal papillae (Fig. 44C). Ventral cirri relatively long, slender. Parapodial glands small, difficult to see, with granular material (Fig. 44A,C). Anterior parapodia each with 5 compound chaetae with unidentate blades (Fig. 44D); blades of dorsal compound chaetae with moderate, straight marginal spines, about 12 µm long, blades of ventral compound chaetae smooth, about 9 µm long. Number of compound chaetae on each parapodium diminishing posteriorly to 3 on posterior parapodia, with thick shafts provided with strong subdistal spur giving bifurcate appearance, and hooked blades, smooth, provided with a long, distinct subdistal spine on most dorsal compound chaetae (Fig. 44G), about 10–9 µm long. Dorsal simple chaetae from chaetiger 1, unidentate, with few subdistal marginal spines (Fig. 44F). Ventral simple chaetae on posterior parapodia, sigmoid, distally hooked, unidentate, smooth, provided with a long, distinct subdistal spine (Fig. 44H). Parapodia each with solitary, slender acicula, bent to a right angle (Fig. 44E,I). Pygidium small, with numerous, rounded papillae, and 2 anal cirri, similar to dorsal cirri but much longer (Fig. 44B). Pharynx through 3 segments; pharyngeal tooth not seen; probably located on anterior rim (Fig. 44A). Proventricle through 1–2 segments, with 12 muscle cell rows.
Remarks. This species is closely related to Sphaerosyllis bifurcata, S. bifurcatoides and S. rotundipapillata, all Australian endemic species, all characterized by having large, distinct dorsal papillae, distally rounded or trilobed, and shafts of compound chaetae distally bifid. Sphaerosyllis voluntariorum is represented by a single specimen, but it is distinctly different to these three species because it is more densely papillated on anterior segments and by having a long, distinct subdistal spine on the ventral simple chaetae and on the blades of dorsalmost, posterior compound chaetae.
Distribution. Australia (Western Australia).
Habitat. On algae, 2 m depth.
Etymology. This species is dedicated to the volunteers of the Marine Invertebrate section of The Australian Museum, who sorted samples from all around Australia, extracting specimens of syllids for this study.
description: Published as part of Guillermo San Martin, 2005, Exogoninae (Polychaeta: Syllidae) from Australia With the Description of a New Genus and Twenty-two New Species, pp. 39-152 in Records of the Australian Museum 57 on pages 89-90, DOI: 10.3853/j.0067-1975.57.2005.1438, http://zenodo.org/record/15343387