Erinaceusyllis horrockensis (Hartmann-Schröder, 1981), 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 : 75-77

Erinaceusyllis horrockensis (Hartmann-Schröder, 1981) n.comb.

Fig. 30A–I

Brania horrockensis Hartmann-Schröder, 1981: 35 , figs. 68–72.

Sphaerosyllis horrockensis .–Hartmann-Schröder, 1982: 71; 1983: 134; 1984: 23; 1985: 70; 1986: 43; 1987: 41; 1989: 28.

Material examined. AUSTRALIA: NEW SOUTH WALES. 1 specimen, AM W26436, 100 m north west of Split Solitary Island, 30°14.0'S 153°10.8'E, mixed red algae, 15 m, S.J. Keable, 7 Mar 1992. 1 specimen, AM W26440, 100 m north west of Split Solitary Island, 30°14.0'S 153°10.8'E, mixed red algae, 15 m, S.J. Keable, 7 Mar 1992. 1 specimen, AM W26441, Richmond River, near shore Ballina, old wharf between Cherry & Martin Sts, 28°52.5'S 153°33.6'E, drift algae, 6 m, S.J. Keable, 5 Mar 1992. 4 specimens, AM W26442, Halfway Reef, 200 m south of Sullivan Reef, Ulladulla, 35°21.42'S 150°29.31'E, airlift over wall of sponges, bryozoa & hydrozoa, 15 m, K. Attwood et al., 3 May 1997. 3 specimens, AM W26533, southwest side of South Solitary Island, 30°12.0'S 153°16.0'E, coral rubble, 18 m, R.T. Springthorpe, 24 Jun 1992. 2 specimens, AM W26544, 100 m north west of Split Solitary Island, 30°14.0'S 153°10.8'E, encrusting algae & ascidians, 16 m, E.L. Albertson, 7 Mar 1992. 7 specimens, AM W26610, Grotto Point, Balmoral Beach, Port Jackson, 33°49'S 151°15'E, algae, 4 m, P. Colman, 18 July 1983. 3 specimens, AM W26612, north east corner of Clark Island, 33°51.85'S 151°14.47'E, encrustation on outside of bottle, 5 m, P.A. Hutchings, 17 Apr 1996. 1 specimen, AM W26644, Bottle and Glass Rocks, Port Jackson, 33°50.9'S 151°16.2'E, airlift, 12 m, G. Clark, 11 Dec 1989. 2 specimens, AM W26705, 100 m north west of Julian Rocks, Byron Bay, 28°36.8'S 153°37.8'E, shell and gravel, 15 m, E.L.Albertson, R.T. Springthorpe & G.D.F. Wilson, 3 Mar 1992. VICTORIA. 6 specimens, MV F62701, Eastern Bass Strait, 11.7 km W of Pt. Ricardo, 37°49.89'S 148°30.13'E, coarse sand, 27 m depth, 4 June 1991. TASMANIA. 3 specimens, AM W27671, north end of beach, 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. SOUTH AUSTRALIA. 4 specimens, AM W26746, Billy Lights Point, Port Lincoln, 34°45'S 135°53'E, stone washings from sheltered intertidal rocks, 0 m, I. Loch, 15 Feb 1985. 1 specimen, AM W26747, Elliston Reef, 33°39'S 134°53'E, algae from reef flat at low tide, P.A. Hutchings, 11 Mar 1979. WESTERN AUSTRALIA. 1 specimen, AM W26671, east side of West Wallabi Island, 28°27.9'S 113°40.9'E, in Posidonia australis root mat, plus epifauna, 2 m, P.A. Hutchings, 26 May 1994.

Description. Body small to minute, 2.7 mm long, 0.15 mm wide, 28 chaetigers, covered with small, scattered papillae ( Fig. 30A ). Prostomium oval, wider than long; 4 large eyes in trapezoidal arrangement, nearly in line, and 2 anterior eyespots; antennae spindle-shaped, basally bulbous; median antenna similar to combined length of prostomium and palps, inserted slightly anteriorly to anterior eyes; lateral antennae shorter than median antenna, inserted slightly anteriorly to median antenna ( Fig. 30A,B ). Palps shorter than prostomium, fused along their length. Peristomium similar in length to following segments; tentacular cirri similar to lateral antennae. Dorsal cirri on all segments; dorsal cirri of chaetiger 1 longer than antennae, dorsal cirri of chaetiger 2 much shorter, basally inflated, sphaerical, progressively longer on midbody, with bulbous bases and short tip ( Fig. 30A ). Compound chaetae heterogomph, with smooth shafts and blades elongate, unidentate, distally slightly hooked, basally with short marginal spines (Fig. 30D,G); anterior parapodia each with 8 compound chaetae, dorsoventral gradation in length, 32 µm above, 14 µm below; posterior parapodia each with 5 compound chaetae, similar to those of anterior parapodia, blades similar but more elongate, about 36 µm above 20 µm below. Dorsal simple chaetae on anterior parapodia, usually from chaetiger 1, distally entire, smooth ( Fig. 30C ) or provided with short marginal spines ( Fig. 30F ). Ventral simple chaetae slender, smooth, indistinctly bidentate ( Fig. 30H ), on posterior parapodia.Acicula solitary, acuminate ( Fig. 30C,I ). Pharynx proportionally slender, through 4 segments; pharyngeal tooth small, oval, located near opening ( Fig. 30A,B ); pharyngeal papillae apparently absent. Proventricle barrelshaped, through 3 segments, with about 17 muscle cell rows. Pygidium small, with two anal cirri similar to dorsal cirri but longer.

Distribution. Australia (Victoria, New South Wales, Tasmania, South Australia, and Western Australia).

Habitat. Coarse sand, shell and gravel, amongst algae, in encrustations, sponges, ascidians and bryozoans, coral rubble; intertidal to 27 m depth.

Figures

Fig. 30. Erinaceusyllis horrockensis. (A) anterior end, dorsal view. (B) prostomium and anterior rim of everted pharynx. (C) dorsal simple chaeta, anterior parapodium. (D) compound chaetae, anterior parapodium. (E) acicula, anterior parapodium. (F) dorsal simple chaeta, posterior parapodium.(G) compound chaetae, posterior parapodium.(H) ventral simple chaeta.(I) acicula, posterior parapodium. Scale A,B: 0.1 mm, C–I: 20 µm.