Exogone (Exogone) goorapuranga

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 : 131-133

Exogone (Exogone) goorapuranga n.sp.

Figs. 80A–K, 81B–D

Material examined. AUSTRALIA: QUEENSLAND. HOLOTYPE: AM W26519, Halifax Bay, north of Townsville, 19°09'S 146°37'E, 5 m, Queensland Nickel Pty Ltd, Feb 1985. PARATYPES (“Queensland Nickel Pty Ltd” is abbreviated QN in the following): 4 specimens, AM W26520, Halifax Bay, north of Townsville, 19°09'S 146°37'E, 5 m, QN, Feb 1985. 1 specimen, AM W21811, Halifax Bay, north of Townsville, 19°09'S 146°37'E, 5 m, QN, Feb 1985. 1 specimen, AM W26521, Halifax Bay, north of Townsville, 19°09'S 146°37'E, 2 m, QN, Feb 1985. 1 specimen, AM W26552, Halifax Bay, north of Townsville, 19°9'S 146°37'E, 5 m, QN, July 1977. 1 specimen, AM W26553, Halifax Bay, north of Townsville, 19°9'S 146°37'E, 5 m, QN, July 1977. 1 specimen, AM W26555, Halifax Bay, north of Townsville, 19°10'S 146°44'E, 5 m, QN, July 1977. 1 specimen, AM W26561, Halifax Bay, north of Townsville, 19°10'S 146°38'E, 5 m, QN, Jan 1977. 2 specimens,AM W26567, Halifax Bay, north of Townsville, 19°9'S 146°37'E, 5 m, QN, July 1977. 2 specimens, AM W26568, Halifax Bay, north of Townsville, 19°09'S 146°37'E, 2 m, QN, Feb 1985. 1 specimen, AM W26572, Halifax Bay, north of Townsville, 19°10'S 146°44'E, 5 m, QN, Jan 1977. 4 specimens, AM W26574, Halifax Bay, north of Townsville, 19°10'S 146°38'E, 5 m, QN, July 1977. 4 specimens, AM W26575, Halifax Bay, north of Townsville, 19°10'S 146°37'E, 2 m, QN, Jan 1977. 1 specimen, AM W26580, Halifax Bay, north of Townsville, 19°7'S 146°33'E, 2 m, QN, Jan 1977. 5 specimens, AM W26581, Halifax Bay, north of Townsville, 19°10'S 146°44'E, 5 m, QN, July 1977. 2 specimens, AM W26584, Halifax Bay, north of Townsville, 19°10'S 146°36'E, 2 m, QN, July 1977. 1 specimen, AM W26585, between bommies inside lagoon entrance, Lizard Island, 14°40'S 145°28'E, medium to fine sediment, 18 m, A.R. Jones & C. Short, 9 Oct 1978. 2 specimens, AM W26586, 600 m SW of Research Point, lagoon, south Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 1 specimen, AM W26587, 100 m off eastern end of Mangrove Beach, south Lizard Island, 14°40'S 145°28'E, 3.6 m, A.R. Jones & C. Short, 11 Oct 1978. 4 specimens, AM W26588, 600 m SW of Research Point, lagoon, south Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 1 specimen, AM W26589, 100 m off eastern end of Mangrove Beach, Lizard Island, 14°40'S 145°28'E, 3.6 m, A.R. Jones & C. Short, 11 Oct 1978. 1 specimen, AM W26590, 600 m SW of Research Point, lagoon, south Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 11 Oct 1978. 1 specimen, AM W26591, lagoon at south end of Lizard Island, 14°40'S 145°28'E, 3.6 m, A.R. Jones & C. Short, 11 Oct 1978. 2 specimens, AM W26592, 400 m off Chinamans Ridge,Watson’s Bay, Lizard Island, 14°40'S 145°28'E, filamentous algae, 12 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26593, 600 m SW of Research Point, lagoon, south Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 1 specimen, AM W26594, 100 m off eastern end of Mangrove Beach, south Lizard Is., 14°40'S 145°28'E, 3.6 m, A.R. Jones & C. Short, 11 Oct 1978. 1 specimen, AM W26595, 100 m off Mangrove Beach, south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 3 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26596, 100 m off Mangrove Beach, south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 3 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26597, 1000 m off Chinamans Ridge, Watson’s Bay, Lizard Island, 14°40'S 145°28'E, seagrasses, 21.2 m, A.R. Jones & C. Short, 13 Oct 1978.1 specimen, AM W26598, 200 m SW of Freshwater Beach, lagoon at south end of Lizard Island, 14°40'S 145°28'E, medium sediment, 3 m, A.R. Jones & C. Short, 10 Oct 1978. 1 specimen, AM W26599, 600 m SW of Research Point, lagoon at south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 4 specimens, AM W26600, 600 m SW of Research Point, lagoon at south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 1 specimen, AM W26601, 100 m off Mangrove Beach, lagoon at south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 3 m, A.R. Jones & C. Short, 13 Oct 1978. 3 specimens, AM W26602, 1000 m off Chinamans Ridge, western coast of Lizard Island, 14°40'S 145°28'E, seagrasses, 21.2 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26603, between bommies inside lagoon entrance, south end of Lizard Island, 14°40'S 145°28'E, medium to fine sediment, 18 m, A.R. Jones & C. Short, 9 Oct 1978. 1 specimen, AM W26604, 100 m off Mangrove Beach, lagoon at south end of Lizard Island, 14°40'S 145°28'E, medium sediment, 3 m, A.R. Jones & C. Short, 13 Oct 1978. 4 specimens, AM W26605, 1000 m off Chinamans Ridge, Watsons Bay, west coast of Lizard Island, 14°40'S 145°28'E, seagrasses, 21.2 m, A.R. Jones & C. Short, 13 Oct 197. 6 specimens, AM W26606, 1 km off Chinamans Ridge, Watsons Bay, Lizard Island, 14°40'S 145°28'E, seagrasses, 21.2 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26607, 400 m off Chinamans Ridge, Watsons Bay, west coast of Lizard Island, 14°40'S 145°28'E, filamentous algae, 12 m, A.R. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W26608, 100 m off Chinamans Ridge, Watsons Bay, west coast of Lizard Island, 14°40'S 145°28'E, sand, 9 m, A.R. Jones & C. Short, 13 Oct 1978. 2 specimens, AM W26609, 600 m west of Research Point, lagoon at south end of Lizard Island, 14°40'S 145°28'E, coarse to medium sediment, 4.5 m, A.R. Jones & C. Short, 10 Oct 1978. 4 specimens, AM W202674, Triangular Island, Shoalwater Bay, 22°23'S 150°31'E, J.A. Lewis & J.R. Forsyth, 1981. WESTERN AUSTRALIA. 1 specimen, AM W27053, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead coral plates covered in coralline algae, 8 m, P.A. Hutchings, 22 May 1994. 2 specimens, AM W27054, southeast end of Long Island, 28°28.8'S 113°46.5'E, dead coral embedded in calcareous substrate, 30 m, P.A. Hutchings, 22 May 1994. 3 specimens, AM W27055, Goss Passage, Beacon Island, 28°25.5'S 113°47.0'E, dead coral substrate embedded in fine sediment, 33 m, P.A. Hutchings, 23 May 1994. 2 specimens, AM W27452, 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 W27661, 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 long, slender, filiform, holotype incomplete, 2.5 mm long, 0.4 mm wide, 26 chaetigers; longest paratype 3 mm long for 35 chaetigers. Prostomium oval, wider than long; 4 eyes in trapezoidal arrangement. Antennae small, originating close to each other near middle of anterior margin of prostomium (Figs. 80A, 81B ); lateral antennae papilliform, median antenna about twice as long as lateral antennae (Figs. 80A, 81B ). Palps long, broad, fused along their length, with a dorsal furrow and a distal notch (Figs. 80A, 81B ). Peristomium similar in length to following segments, covering dorsal posterior part of prostomium; tentacular cirri minute, smaller than lateral antennae. Dorsal cirri ovoid, shorter than parapodial lobes, similar in size to lateral antennae, present on all segments (Figs. 80A, 81B ). Anteriormost 6 chaetigers each with 5–6 compound falcigers, blades with subdistal tooth long and wide, distal tooth small, marginally smooth, shafts provided with long spines (Fig. 80C), blades about 6 µm long, without spinigerlike chaetae. From about chaetiger 7 posteriorly, parapodia each with 1 compound spiniger-like chaeta, with short, unidentate blade, 7–8 µm long, with long marginal spines (Fig. 80F), and 3 falcigers similar to those of anterior parapodia but shorter (Fig. 80G), 2–3 µm long; shafts of all compound chaetae provided with long, fine subdistal spines. Progressively posteriorly, both shafts and blades become less spinose; posterior parapodia each with 1 compound spiniger-like chaeta, with filiform, minute, smooth blade and distally enlarged, nearly smooth shaft (Fig. 80I), and 2 falcigers, with smooth shafts and minute blades (Fig. 80J). Dorsal simple chaetae from anterior parapodia, smooth, bidentate, subdistal tooth long and distal tooth minute (Fig. 80B), thicker and provided with relatively longer distal tooth posteriorly (Fig. 80E,H). Ventral simple chaetae on posterior parapodia, sigmoid, smooth, similar to posterior dorsal simple chaetae (Fig. 80K). Acicula solitary, slender, distally rounded (Fig. 80D). Pharynx short and relatively wide, through 3 segments; lateral muscles of pharynx distinct, giving appearance of one gland on each side (Fig. 80A); pharyngeal tooth wide and long (Fig. 80A). Proventricle short, through 2 segments, with 18 muscle cell rows. Pygidium with 2 long anal cirri ( Fig. 81D ).

Remarks. Apparently, Exogone (E.) goorapuranga n.sp. resembles E. naidina ; it lacks, however, compound chaetae with modified blades on anteriormost parapodia, and the shafts of compound chaetae have long, hair-like spines. Probably, some records of E. (E.) naidina from Australia should be referred to Exogone (E.) goorapuranga .

Distribution. Australia (Queensland, Western Australia).

Habitat. On fine to coarse sediment, inside dead corals, algae; intertidal to 33 m depth.

Etymology. The name of the species is derived from the combination of two Aboriginal words, goora which means, amongst others, long, and puranga, which means hairs, in reference to the long hairs or spines on shafts of compound chaetae.

Figures

Fig. 81. SEM of Exogone (Exogone) longicornis, (A) anterior end, dorsal view. SEM of Exogone (Exogone) goorapuranga, (B) anterior end, dorsal view. (C) detail of nuchal organs. (D) posterior end, lateral view. SEM of Exogone (Exogone) breviantennata, A, anterior end, dorsal view. SEM of Exogone (Exogone) dispar, A, anterior end, dorsal view.