Sphaerosyllis georgeharrisoni, Guillermo San Martin, 2005

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 : 97-99

Sphaerosyllis georgeharrisoni n.sp.

Figs. 53D–F , 54A–H

Material examined AUSTRALIA: WESTERN AUSTRALIA. HOLOTYPE, AM W28657, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead coral plates covered in coralline algae, 8 m, P. Hutchings, 22 May 1994. PARATYPE, 1 specimen, AM W27123, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead coral plates covered in coralline algae, 8 m, P. Hutchings, 22 May 1994. PARATYPE, 1 specimen, AM W27128, northeast entrance to Goss Passage, Beacon Island, 28°27.9'S 113°46.7'E, dead plate-like Acropora covered in coralline algae, 8 m, P. Hutchings, 25 May 1994. PARATYPE, 1 specimen, AM W28658, off south end of Long Island, Beacon Island, 28°28.8'S 113°46.3'E, dead coral substrate covered in coralline algae, 5 m, P. Hutchings, 25 May 1994. 2 specimens, AM W27122, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead Acropora plates covered in coralline algae, 8 m, P. Hutchings, 19 May 1994. 22 specimens, AM W27124, 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. 4 specimens, AM W27125, north end of Long Island, 28°27.9'S 113°46.3'E, dead coral substrate with coralline & brown algae, 6 m, C. Bryce, 22 May 1994. 5 specimens, AM W27126, off jetty near Fisheries Hut, Beacon Island, 28°25.5'S 113°47.0'E, dead plate-coral substrate— Acropora , Montipora spp. , 12 m, P. Hutchings, 23 May 1994.1 specimen, AM W27127, West Deacon Island, 28°28.6'S 113°48.4'E, attached to dead coral, 7 m, A. Brearley, 21 May 1994. 3 specimens, AM W27129, off south end of Long Island, Beacon Island, 28°28.8'S 113°46.3'E, dead coral substrate covered in coralline algae, 5 m, P. Hutchings, 25 May 1994.1 specimen on SEM stub, AM W27677, 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 and R.T. Springthorpe, 6 Jan 1984.

Description. Body small, slender ( Fig. 53D ), 2.3 mm long, 0.12 mm wide, 26 chaetigers; dorsum covered with small papillae, extended to palps and parapodia, numerous on midbody (Fig. 54A). Prostomium rectangular, mostly covered by peristomium ( Figs. 53E , 54A); 4 eyes in trapezoidal arrangement. Antennae similar in length to prostomium or slightly shorter, all similar, with bulbous bases and moderate tip; lateral antennae inserted on anterior margin, median antenna inserted slightly posteriorly ( Fig. 53E ), just in front of anterior eyes (Fig. 54A). Tentacular cirri similar to antennae but shorter. Dorsal cirri short, similar to tentacular cirri ( Figs. 53E , 54A). Parapodial glands large, with granular or hyaline material, usually both kinds of material in the same specimen (Fig. 54A); some specimens with parapodial glands difficult to see.Anterior parapodia each with about 5 compound chaetae, blades unidentate, provided with moderately long marginal spines, longer on dorsal chaetae (Fig. 54C), with marked dorsoventral gradation in length, about 20 µm above, 10 µm below. Posteriorly, number of compound chaetae on each parapodium decreasing to 3 on posterior parapodia, with larger shafts and blades shorter, about 12–10 µm long, slightly hooked, smooth or provided with short marginal spines (Fig. 54F). Dorsal simple chaetae from chaetiger 1, unidentate, provided with moderately long marginal spines (Fig. 54B,E). Ventral simple chaetae on posterior parapodia, sigmoid, unidentate, smooth (Fig. 54G). Acicula solitary, with tips bent at right angle (Fig. 54D). Pygidium small, provided with few (5–7) long papillae and 2 anal cirri, similar in shape to dorsal cirri but longer ( Figs. 53F , 54H). Pharynx slender, through 3 segments; pharyngeal tooth anteriorly located. Proventricle small, through 1 segment, with 13–14 muscle cell rows.

Remarks. This species is characterized by its large parapodial glands with hyaline material, small size, short proventricle, median antenna inserted slightly posteriorly to lateral antennae, and long pygidial papillae. Juveniles of S. hirsuta appear to be similar and difficult to discriminate. Sphaerosyllis pygipapillata has all antennae in line, apparently smooth dorsum, and the pygidial papillae are longer and slender.

Distribution. Australia (Western Australia).

Habitat. Associated with dead corals, also in medium sand on coral reefs, in shallow waters.

Etymology. This species is named in honour of Mr George Harrison, ex-Beatle and one of my favourite musicians, who passed away recently.

Figures

Fig. 53. SEM of Sphaerosyllis lateropapillata. (A) anterior end, dorsal view. (B) midbody, dorsal view. (C) midbody parapodia, dorsal view. SEM of Sphaerosyllis georgeharrisoni. (D) dorsal view of a complete specimen. (E) anterior end, dorsal view. (F) posterior end, dorsal view.