Erinaceusyllis kathrynae, 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 : 83-86

Erinaceusyllis kathrynae n.sp.

Figs. 40A–H, 41A–F

Material examined.AUSTRALIA:NEW SOUTH WALES. HOLOTYPE: AM W26400, southwest side of South Solitary Island, Australia, 30°12.0'S 153°16.0'E, coral rubble, 18 m, R.T. Springthorpe, 24 Jun 1992. PARATYPE: 1 specimen, AM W26401, Northern side of Bannister Head, 35°19.15'S 150°29.12'E, grey sponge from top of boulder, 18 m, K. Attwood, 6 May 1997. PARATYPE: 1 specimen, AM W26402, southwest side of South Solitary Island, 30°12.0'S 153°16.0'E, coral rubble, 18 m, R.T. Springthorpe, 24 Jun 1992. 1 specimen, AM W26408, 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. WESTERN AUSTRALIA. 2 specimens, AM W26815, reef west of groyne, 2 km south of Cape Peron, 32°16'S 115°41'E, orange sponge in deep channel of limestone reef, 4.5 m, R.T. Springthorpe, 26 Dec 1983. 2 specimens on SEM stub, AM W26817, Red Bluff, Kalbarri, 27°42'S 114°09'E, mixed coralline algae from rocky shore, 4 m, J.K. Lowry, 10 Jan 1984. 2 specimens, AM W26826, 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.

Description. Body small, holotype 2.3 mm long, 0.16 mm wide, 30 chaetigers, longest paratype 3.1 mm long, 34 chaetigers. Small, scattered papillae on dorsum and palps, more abundant on lateral margins of segments (Figs. 40A, 41A–D ). Prostomium oval, wider than long; 4 large eyes in trapezoidal arrangement and 2 anterior eyespots; antennae spindle-shaped, with bulbous bases and short tips, median antenna similar to combined length of prostomium and palps, inserted between eyes, lateral antennae shorter than median antenna, located near anterior margin, lateral to eyespots. Palps shorter than prostomium, basal half fused, with distinct terminal notch, forming a bilobed structure (Figs. 40A, 41A–C ), provided with few, small papillae. Peristomium similar in length to following segments, bilobed, forming 2 anterior lateral wings, covering dorsally posterior margin of prostomium (Figs. 40A, 41B,C ); tentacular cirri similar to antennae but smaller. Dorsal cirri shorter than antennae, longer than tentacular cirri, with bulbous bases and short tips, absent on chaetiger 2 ( Fig. 41A ), more elongate in midbody segments ( Fig. 41D ). Parapodia conical, with a few papillae. Compound chaetae heterogomph, blades marginally smooth or provided with short, straight spines on longer blades, unidentate, distally slightly hooked (Figs. 40D,F, 41E,F ); anterior parapodia each with 5–7 compound chaetae with usual dorsoventral gradation in length (Fig. 40D), 22–13 µm long, 4 compound chaetae on each posterior parapodia, similar to those of anterior parapodia (Fig. 40F). Dorsal simple chaetae from from chaetiger 1, unidentate, provided with short marginal spines (Fig. 40C,E). Ventral simple chaetae from midbody, slender, smooth, unidentate (Fig. 40G). Acicula solitary, acuminate, with a long, filiform tip (Fig. 40H). Pharynx proportionally slender, through 3 segments; pharyngeal tooth rhomboidal, small, located near opening (Fig. 40A). Proventricle long and wide, barrel-shaped, through 3 segments, with about 15–17 muscle cell rows. Pygidium small, with numerous long papillae, anal cirri elongate (Fig. 40B).

Remarks. Erinaceusyllis kathrynae n.sp. is similar to E. cirripapillata , but it lacks the characteristic papillae on the cirri; Sphaerosyllis perspicax Ehlers, 1908 , which probably belongs to Erinaceusyllis , is also similar, but the anterior dorsal cirri are strongly inflated at their bases, the eyes and the antennae are both arranged in line, and the palps are completely fused all along their length (Ehlers, 1908).

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

Habitat. Coral rubble, sponges, encrusting and coralline algae, 3–18 m depth.

Etymology. This species is named in honour of Kathryn (Kate) Attwood, of The Australian Museum.

Figures

Fig.41 (facing page).SEM of Erinaceusyllis kathrynae n.sp. (A) dorsal view, anterior end and midbody.(B) prostomium, peristomium and chaetiger 1 (median antenna missing). (C) anterior end, frontal view. (D) midbody parapodia, dorsal view. (E) compound chaeta, anterior parapodium. (F) compound chaeta, posterior parapodium.