Odontosyllis annulatus ( Hartmann-Schröder, 1979 )

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 : 283

Odontosyllis annulatus ( Hartmann-Schröder, 1979)

Fig. 18A–G

Odontoautolytus annulatus Hartmann-Schröder, 1979: 112 , figs 178–182.

Odontosyllis brevicirra Hartmann-Schröder, 1991: 34 , figs 54–56.

Material examined. AUSTRALIA: WESTERN AUSTRALIA: Port Hedland , 19°38'S 119°31'E, coarse sediments, intertidal, 28 Sept. 1975, holotype of Odontoautolytus annulatus ( ZMH P-15482) and 2 paratypes ( ZMH P-15483) . QUEENSLAND: Gladstone , 23°49'S 151°25'E, coarse sand, 28 Jan 1976, holotype of Odontosyllis brevicirra ( HZM P- 20543) and 1 paratype ( HZM P-20544). All material collected Hartmann-Schröder .

Description. Body long, slender, ( Fig. 18A), about 4.8 mm long, 0.3 mm wide, with 47 chaetigers. Prostomium oval, laterally convex, with 2 lateral and 2 frontal tufts of cilia ( Fig. 18A); 4 eyes in rectangular arrangement, those of anterior pair slightly larger than posterior ones; antennae short, digitiform, shorter than prostomium; median antenna inserted between anterior eyes; lateral antennae inserted near anterior margin, close to each other, near midline of margin ( Fig. 18A). Palps shorter than prostomium, blunt. Peristomium shorter than subsequent segments; tentacular cirri similar to antennae; dorsal ones longer than ventral ones. Occipital flap absent, although some with peristomium ones, similar in shape and size to dorsal tentacular cirri. Ventral cirri fused with parapodial lobes, inserted distally ( Fig. 18A,D). Parapodia each with 4 compound chaetae ( Fig. 18D), strongly heterogomph, shafts with subdistal large tooth, and short, smooth, triangular, bidentate blades, subdistal tooth small, all similar in shape and length ( Fig. 18E), 7–8 µm in length. Solitary ventral simple chaeta on far posterior parapodia of one specimen, slender, smooth, unidentate ( Fig. 18G). Dorsal simple chaetae not observed. Solitary acicula on each parapodium, distally acuminate ( Fig. 18F). Pygidium large, slightly bilobed, with 2 long, slender, filiform anal cirri ( Fig. 18B). Pharynx through about 2 segments, according to original description, trepan with 6 small teeth ( Fig. 18C); dark gland near pharynx opening ( Fig. 18C). Proventricle long and slender, through about 7–8 segments ( Fig. 18A), with about 50 muscle cell rows.

Remarks. This species has small ventral cirri, inserted distally. Hartmann-Schröder (1979) made an incorrect interpretation of the parapodia, overlooked the ventral cirri and described it as a new genus, which she placed in the subfamily Autolytinae . Nygren (2004) synonymized Odontoautolytus with Odontosyllis . After examination of the type series of both species, Odontoautolytus annulatus and Odontosyllis brevicirra , we suggest that they represent the same species Odontosyllis annulatus .

Habitat. Occurring in coarse sediments, intertidally.

Distribution. Australia (Western Australia, Queensland).