Sphaerosyllis densopapillata Hartmann-Schröder, 1979

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 : 92-94

Sphaerosyllis densopapillata Hartmann-Schröder, 1979

Figs. 48A–H, 49A,B

Sphaerosyllis capensis densopapillata Hartmann-Schröder, 1979: 104 , figs. 141–143; 1980: 54; 1981: 36; 1982: 69; 1990: 53.

Sphaerosyllis cuticulata Hartmann-Schröder, 1991 (in part): 41, figs. 68–72.

Material examined. AUSTRALIA: QUEENSLAND. 2 specimens, AM W26566, Halifax Bay, north of Townsville, 19°10'S 146°44'E, 5 m, Queensland Nickel Pty Ltd, July 1977. 2 specimens, AM W26577, Halifax Bay, north of Townsville, 19°10'S 146°44'E, 5 m, Queensland Nickel Pty Ltd, Jan 1977. 1 specimen,AM W26714, 100 m off Mangrove Beach, Lizard Island, 14°40'S 145°28'E, medium sediment, 3 m, C. Short & A.R. Jones, 13 Oct 1978. 2 specimens, AM W26933, Hinchinbrook Channel, 18°20'S 146°4'E, tidal flats (mud & sand), S. Dittmann, 14 Oct 1989. WESTERN AUSTRALIA. 4 specimens, AM W17727, Exmouth, near Tantabiddy Creek, 21°56'S 113°58'E, algae & crusts, G. Hartmann-Schröder, 11 Jan 1975. 1 specimen, AM W26626, off south end of Long Island, Beacon Island, 28°28.8'S 113°46.3'E, dead coral covered in coralline algae, 5 m, P.A. Hutchings, 25 May 1994. 3 specimens, AM W26627, east side of Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, intertidal; fauna in sand under boulders; very low tide, 0 m, P.A. Hutchings, 24 May 1994. 1 specimen, AM W26628, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead Acropora with coralline algae, sponges & ascidians, 23 m, P.A. Hutchings, 19 May 1994. 7 specimens, AM W26629, north end of Long Island, Goss Passage, 28°28.3'S 113°46.3'E, dead coral covered with coralline algae & boring bivalves, 8 m, C. Bryce, 22 May 1994. 1 specimen, AM W26630, south west corner of Lucas Island, Kimberleys, 15°13'S 124°31'E, 30 m, P.A. Hutchings, 24 July 1988. 46 specimens, AM W26631, north end of Long Island, Goss Passage, 28°27.9'S 113°46.3'E, dead coral covered in coralline algae & brown algae, 6 m, C. Bryce, 22 May 1994. 50 specimens and 6 specimens on SEM stub,AM W27641, north end of beach, Bundegi Reef, Exmouth Gulf, 21°49'S 114°11'E, rocky rubble, brown algae with epiphytes, sediment, 2 m, H.E. Stoddart, 4 Jan 1984. 1 specimens, AM W27647, Lafontaine Island, Kimberley region, 14°10'S 125°47'E, 15 m, P.A. Hutchings, 19 July 1988. 11 specimens, AM W27648, north end of beach, Bundegi Reef, Exmouth Gulf, 21°49'S 114°11'E, rocky rubble, coralline algae with green epiphyte, 2 m, H.E. Stoddart, 4 Jan 1984. 1 specimen, AM W27655, inshore reef off Ned’s Camp, Cape Range National Park, 21°59'S 113°59'E, frilly Caulerpa sp. , 1 m, J.K. Lowry, 2 Jan 1984. 1 specimen, AM W27659, 5 km offshore, Bush Bay, 30 km south of Carnarvon, 25°10'S 113°39'E, airlift in strap-leaved seagrass beds, 2 m, J.K. Lowry & R.T. Springthorpe, 6 Jan 1984.

Additional material. HOLOTYPE. HZM P-20560, Heron Island, G. Hartmann-Schröder.

Description. Body small, relatively short, up to 2.5 mm long, 0.12 mm wide, 26 chaetigers. Dorsal surface provided with numerous, rounded papillae, present from peristomium to pygidium (Figs. 48A,B, 49A,B ). Prostomium rectangular; 4 eyes in rectangular to trapezoidal arrangement, close to each other on each side. Antennae inserted on anterior margin of prostomium, all similar or median antenna slightly longer than lateral antennae, all longer than palps, shorter than combined length of prostomium and palps (Figs. 48A,

49B ). Palps similar in length to prostomium, sometimes ventrally folded. Peristomium dorsally covering posterior part of prostomium, similar in length to following segments; tentacular cirri slightly shorter than antennae. Dorsal cirri similar to tentacular cirri, slightly elongate (Fig. 48A), especially on far posterior segments (Fig. 48B). Small, indistinct parapodial glands with hyaline to granular material from chaetiger 4 (Fig. 48A), difficult to see. Anterior parapodia each with about 6 compound chaetae, numbers declining posteriorly to 3 on posterior parapodia; strong dorsoventral gradation in length of blades, especially on anterior segments, 36 µm above 16 µm below (Fig. 48E), less marked on posterior parapodia, 24 µm above 14 µm below (Fig. 48G); longer blades provided with long marginal spines basally, spines shorter on ventral and posterior chaetae. Dorsal simple chaetae from anterior parapodia, curved, unidentate, provided with short marginal spines (Fig. 48C), slightly thicker on posterior parapodia (Fig. 48F). Ventral simple chaetae on posterior parapodia, sigmoid, smooth, unidentate. Acicula solitary, distally bent at right angle (Fig. 48D), thicker posteriorly (Fig. 48H). Pharynx through 3–4 segments; pharyngeal tooth relatively long (Fig. 48A). Proventricle small, through 2 segments, with 13–14 muscle cell rows. Pygidium small, with two anal cirri similar to dorsal cirri but longer (Fig. 48B).

Remarks. Sphaerosyllis densopapillata , originally described as a subspecies of S. capensis , is similar to S. magnidentata Perkins, 1981 from Florida, Bahamas, Cuba, Belize, and the Canary Islands. Both species have a similar size, arrangement of antennae, parapodial glands small, with hyaline contents, and a large pharyngeal tooth (see Perkins, 1981; Russell, 1991; Núñez et al., 1992). Sphaerosyllis densopapillata , however, has many more dorsal papillae; juvenile specimens have a less densely papillated dorsum, and the papillae are more difficult to see on specimens covered by a dense coat of detritus. I have examined the holotype and 11 paratypes of the species S. cuticulata Hartmann-Schröder, 1991; the holotype appears to be a juvenile specimen of S. densopapillata , with less papillated dorsum than the larger specimens; the paratypes belong to S. capensis (see below).

Distribution. Australia (Western Australia, Queensland, New South Wales).

Habitat. Sand, from fine to coarse. Amongst algae, inside corals and coralline algae. Intertidal to about 30 m depth.

Figures

Fig. 49. SEM of Sphaerosyllis densopapillata. (A) dorsal view, mature male with natatory chaetae. (B) anterior end, dorsal view. SEM of Sphaerosyllis capensis. (C) anterior end, dorsal view. (D) midbody parapodia. (E) anterior compound chaetae. (F) chaetal bundle.