Exogone (Parexogone) caribensis, San Martin, 1991

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 : 120-121

Exogone (Parexogone) caribensis San Martín, 1991

Fig. 72A–I

Exogone (Parexogone) caribensis San Martín, 1991a: 725, fig. 5; San Martín et al., 1996: 251, fig. 2; San Martín, 2003: 248, figs. 134, 135.

Material examined. AUSTRALIA: QUEENSLAND. 1 specimen, AM W27014, 100 m off Mangrove Beach in lagoon, Lizard Island, 14°40'S 145°28'E, coarse to medium sand, 3 m, A. Jones & C. Short, 13 Oct 1978. 1 specimen, AM W27015, inside lagoon entrance, Lizard Island, 14°40'S 145°28'E, medium to fine sand, 18 m, A. Jones & C. Short, 9 Oct 1978. TASMANIA. 3 specimens,AM W27673, near freshwater stream, Parsons Cove, Freycinet National Park, 42°08.6'S 148°16.9'E, clean gravelly sand, intertidal, 0 m, N.W. Riser, 24 Jan 1986. WESTERN AUSTRALIA. 1 specimen, AM W26796, southeast end of Long Island, 28°28.8'S 113°46.5'E, dead coral substrate embedded in calcareous substrate, 30 m, P.A. Hutchings, 22 May 1994. 3 specimens, AM W27012, 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 W27013, Wallabi Island group, 28°27.05'S 113°45.10'E, scallop beds medium to fine sand with shell debris, 38 m, P.A. Hutchings on FRV “Flinders”, 30 May 1994. 1 specimen, AM W27442, 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.

Description. Body small, thin, about 3.6 mm long, 0.24 mm wide, 37 chaetigers. Prostomium ovate to rectangular, wider than long; 4 small eyes in trapezoidal arrangement and 2 anterior eyespots (Fig. 72A); antennae inserted close to each other, between posterior eyes; median antenna cylindrical, much longer than lateral antennae, shorter than combined length of prostomium and palps; lateral antennae minute, papilliform. Palps long, broad, fused along their length, slightly longer than prostomium (Fig. 72A). Tentacular and dorsal cirri minute, papilliform; dorsal cirri absent on chaetiger 2 (Fig. 72A). Anterior parapodia each with 1–2 compound chaetae with blades long, distally rounded unidentate or provided with minute subdistal tooth, and short, coarse marginal spines (Fig. 72C), about 25 µm long; in addition 10–12 compound chaetae with short blades, unidentate or sub-bidentate, margin coarsely serrated (Fig. 72D), 9 µm long. Blades of spiniger-like chaetae slightly longer (Fig. 72G) on midbody, about 36 µm long, falcigers similar (Fig. 72H); midbody parapodia each with solitary spiniger-like chaeta and 4–5 falcigers; posterior parapodia each with only 3–4 falcigers. Dorsal simple chaetae from anterior parapodia, unidentate, subdistally serrated (Fig. 72B), thicker and smooth on posterior parapodia (Fig. 72E). Ventral simple chaetae on posterior parapodia, sigmoid, unidentate, smooth (Fig. 72F). Acicula solitary, distally expanded and rounded (Fig. 72I). Pharynx long, through about 4–5 segments; pharyngeal tooth conical, on anterior rim (Fig. 72A). Proventricle slightly shorter than pharynx, through 5–6 segments, with about 23 muscle cell rows. Pygidium with 2 long anal cirri.

Distribution. USA (Florida and Gulf of México). Capbreton Canyon (between Spain and France). Eastern Mediterranean. Australia (Queensland, Tasmania, Western Australia).

Habitat. Sandy sediments, from shallow waters to 1,100 m depth; occasionally young specimens on algae.