Pionosyllis mariae, San Martin & Hutchings, 2006

San Martin, G & Hutchings, PA, 2006, Eusyllinae (Polychaeta: Syllidae) from Australia with the Description of a New Genus and Fifteen New Species, Records of the Australian Museum 58, pp. 257-370 : 340-345

Pionosyllis mariae n.sp.

Figs 46D–F, 70A–J, 71A–F, 72A–C

Material examined. HOLOTYPE ( AM W28454) AUSTRALIA: QUEENSLAND: Outer Yonge Reef, Great Barrier Reef, 14°36'S 145°38'E, rock with Lithothamnion & Halimeda , 30 m, coll. P.A. Hutchings, 24 Jan 1977. PARATYPE ( AM W28921) Outer Yonge Reef, Great Barrier Reef, 14°36'S 145°38'E, rock covered with pink coralline algae, encrusting sponges, 9 m, coll. P.A. Hutchings, 21 Jan 1977.

Other material examined. NEW SOUTH WALES: Taupo Seamount, Tasman Sea , 33°16.85'S 156°09.15'E, limestone & sand bottom, 244 m, coll. J.K. Lowry & party on RV Franklin, 2 May 1989, 1 on SEM stub ( AM W28873) .

Description. Body slender, filiform ( Fig. 46D), 7 mm long, 0.3 mm wide, 54 chaetigers. Prostomium pentagonal to triangular, with 4 eyes in open trapezoidal arrangement, and sometimes 2 anterior eyespots. After fixation, however, eyes may be absent ( Fig. 70A). Lateral antennae inserted between anterior eyes and eyespots, near anterior margin of prostomium, smooth, similar in length to palps; median antenna arising between posterior eyes, long, often curled, distally pseudoarticulated, broken on holotype ( Fig. 70A), more than twice length of prostomium. Palps longer than prostomium, triangular, directed behind, fused basally. Two transverse, small, ciliated furrows on prostomium ( Figs 46F arrow, 70A). Peristomium distinct, slightly shorter than subsequent segments; tentacular cirri elongated, dorsal tentacular cirri longer than lateral antennae, shorter than median one, ventral tentacular cirri shorter than dorsal ones ( Figs 46E,F, 70A). Dorsal cirri of chaetiger 1 long, slender, similar to median antenna, sometimes pseudoarticulated distally. Dorsal cirri short, slightly longer than parapodial lobes, fusiform ( Fig. 71A,B), distally more or less truncated ( Fig. 70A,C), usually with some fibrillar inclusions, with terminal pore ( Fig. 71C arrow). Dorsal cirri absent on chaetiger 2, tuft of cilia present ( Fig. 46E,F arrow). Parapodia conical, with distal papilla ( Figs 70C, 71A). Ventral cirri digitiform, slender, slightly longer than parapodial lobes on posterior parapodia. Compound chaetae with hemigomph articulation, smooth distally on shafts; blades of 2 kinds, most dorsal chaetae with elongated, short spiniger-like, bidentate blades, spines on margin apparently jointed by membrane ( Figs 70D,I, 71F), remaining chaetae with short, bidentate blades, with short spines on margin ( Figs 70E, 71E), more strongly bidentate on posterior parapodia ( Figs 70H, 72A). Anterior parapodia each with 1 compound chaetae with elongated blade, about 27 µm in length, and 4 chaetae with shorter blades, 17–12 µm in length; posterior parapodia with 1 compound chaetae with elongate blade and 2–3 short-bladed, all similar in size to anterior ones. Dorsal simple chaetae from midbody, smooth, distally truncate ( Fig. 72B), with small, indistinct hood ( Fig. 70G). Ventral simple chaetae from mid-posterior parapodia, large, acicular, prominent, with subdistal translucent hood, bidentate, proximal tooth long, hooked, distal tooth smaller, also hooked ( Figs 70J, 71E, 72C). Anterior parapodia each with 2 aciculae, one straight, other bent at tip ( Fig. 70F); solitary acicula on remaining parapodia, bent tip, thicker than anterior ones. Dark glands on each parapodia from midbody ( Fig. 70B) with dorsal pores ( Fig. 71C,D arrows). Pharynx through about 4 segments; pharyngeal tooth anteriorly located ( Fig. 70A). Proventricle rectangular, through 3–4 segments, with 30–36 muscle cell rows.

Pygidium semi-circular, with 2 long, slender anal cirri ( Fig.

70B), similar in length to median antenna. Mature specimen with notoacicula and natatory chaetae from chaetiger 17. One specimen epigamic, with natatory chaetae on midbody and posterior segments ( Fig. 71B).

Remarks. Pionosyllis mariae n.sp. is similar to P. weismanni Langerhans, 1879 , a worldwide reported species, that probably represents a complex of morphologically similar species (San Martín, 2003), since small differences among specimens from different parts of the world have been reported (see Ben-Eliahu, 1977). The Australian specimens are distinctly smaller than those of the Mediterranean Sea

(7 mm versus 18 mm) and lack dorsal cirri on chaetiger 2,

which are always present on Mediterranean specimens (see San Martín, 2003).

Habitat. Occurring as cryptic species in encrusting communities and in sand, in depths of 9 to 244 m.

Distribution. Australia (Queensland, New South Wales).

Etymology. The new species is named after María Capa, collaborator and friend.

with elongated blades and having distally pointed dorsal simple chaetae; and ventral simple chaetae bidentate with teeth at 90°.

Habitat. Occurring on encrusting Lithothamnion and Halimeda at depths of 30 m.

Distribution. Australia (Queensland).

Etymology. The species is named after María Teresa Aguado (Mayte), collaborator and friend.