Prosphaerosyllis nathani

Prosphaerosyllis nathani View in CoL San Martín & López, 1998

Figs. 19A–H, 20A–D

Sphaerosyllis (Prosphaerosyllis) nathani View in CoL San Martín & López, 1998: 241, fig. 1.

Material examined.AUSTRALIA: NEW SOUTH WALES. HOLOTYPE: AM W22146, 300 m north east of Green Point, Hawkesbury River, 33°34'S 151°13.5'E, sandy mud, 5 m, A.R. Jones & A. Murray, 11 Feb 1981. 1 specimen, AM W196433, Green Point—Croppy Point, Hawkesbury River, 33°33.5'S 151°14.5'E, mud, 6 m, A. Jones et al., 03 Nov 1977. QUEENSLAND. 1 specimen, AM W26564, Halifax Bay, north of Townsville, 19°9'S 146°37'E, 5 m, Queensland Nickel Pty Ltd, July 1977. TASMANIA. 1 specimen on SEM stub, AM W27988, north end of beach, Parsons Cove, Freycinet National Park, 42°08.6'S 148°16.9'E, clean gravelly sand, intertidal, N.W. Riser, 24 Jan 1986. WESTERN AUSTRALIA. Paratype: 1 specimens,AM W23142, reef south of Lucas Island, 15°16'S 124°29'E, 2 m, P.A. Hutchings, 24 July 1988. 1 specimen, AM W26715, off end of South Mole, Arthur Head, Fremantle, 32°03'S 115°44'E, orange tunicates, 6 m, J.K. Lowry, 25 Dec 1983.

Additional material. NEW ZEALAND. Paratype: 1 specimens, AM W23483 , Kaikoura, 42°24'S 173°41'E, holdfast of Laminaria, N.W. Riser. GoogleMaps

Description. Body small, 2.5 mm long, 0.24 mm wide, 28 chaetigers. Prostomium rectangular, partially covered by peristomium (Fig. 19A,B); 4 large eyes in rectangular arrangement, close to each other on each side and 2 small anterior eyespots; antennae short, with bulbous base and short tip (Figs. 19A,B, 20B); lateral antennae inserted on anterior margin of prostomium, median antenna inserted more posteriorly than lateral antennae. Palps fused to prostomium, broad and short, usually ventrally folded, bearing scattered short papillae (Figs. 19A,B, 20B). Peristomium covering totally or partially prostomium; tentacular cirri similar in shape to antennae but smaller (Figs. 19A,B, 20B). Dorsum covered by debris; dorsal papillae long, thin, digitiform, arranged in 3 irregular dorsal rows (Fig. 19A); each segment also bearing solitary papilla dorsolaterally between dorsal cirri; as result, there are 5 papillae dorsally visible on each segment (Figs. 19A, 20C). Ventral side with long papillae, similar to dorsal papillae, also arranged in 5 irregular rows. Dorsal cirri on all chaetigers; dorsal cirri of anterior segments slightly elongate in some specimens, similar in length to parapodial lobes (Figs. 19A,B), shorter in other specimens, similar to antennae (Fig. 20B); those of remaining segments proportionally long, distinctly longer than parapodial lobes (Figs. 19A,G, 20A,C); dorsal cirri becoming shorter at posterior end of body. Ventral cirri relatively long, digitiform. Parapodial lobes elongate, conical, each with small anterior papilla, inconspicuous prechaetal papilla and long postchaetal papilla (Figs. 19A,G). Parapodia each with about 4 compound chaetae, similar throughout, heterogomph, with blades unidentate and slightly falciform (Fig. 20D), dorsal blades with short marginal spines, ventral ones smooth (Fig. 19D); all blades about 16 µm long. Dorsal simple chaetae from chaetiger 1, thin, smooth, sigmoid (Fig. 19C). Ventral simple chaetae on posterior parapodia, similar to dorsal one (Fig. 19E). Acicula solitary, acuminate (Fig. 19F). Pygidium semi-circular, with two long, thick anal cirri (Fig. 19H). Pharynx through about 4 segments; pharyngeal tooth oval, located well posteriorly from anterior margin, just anteriorly to middle of pharynx (Figs. 19A,B). Proventricle long and wide, through 3–4 segments, with 25 muscle cell rows.

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

Habitat. Mud, sand, also on tunicates and holdfasts; on shallow depths.