Syllis pharobroomensis ( Hartmann-Schröder, 1979 ) Martín & Lucas & Hutchings, 2023

Martín, Guillermo San, Lucas, Yolanda & Hutchings, Pat, 2023, The genus Syllis Savigny in Lamarck, 1881 (Annelida: Syllidae: Syllinae) from Australia (Part 3): new species and redescription of previously described species, Zootaxa 5230 (3), pp. 251-295 : 275-277

Syllis pharobroomensis ( Hartmann-Schröder, 1979) , n. comb.

Figure 13

Typosyllis (Typosyllis) pharobroomensis Hartmann-Schröder, 1979: 92 , Figs 77–81.

Typosyllis pharobroomensis .— Licher 1999: 269.

Material examined. AUSTRALIA, WESTERN AUSTRALIA: Houtman Abrolhos Islands, Goss Passage, north end of Long Island , 28° 28’ 18” S, 113° 46’ 18” E, coll. 22 May 1994, 8 m, hand collected on SCUBA, dead coral covered in coralline algae, AM W.53795, 6 specimens . Houtman Abrolhos Islands, off south end of Long Island, Beacon Island , 28° 28’ 48” S, 113° 46’ 18” E, coll. 25 May 1994, 4 m, hand collected on SCUBA, dead coral covered in coralline algae, AM W.53794, 2 specimens . WA 362 , Cape Range National Park , inshore limestone reef off Neds Camp, 21° 59’ S, 113° 55’ E, coll. 02 Jan 1984, hand collected intertidally in Caulerpa, AM W. 53793, 2 specimens . St. 115, Kimberley region, Shirley Island , 16° 17’S, 123° 26’ E, coll. 26 July 1988, coll P. Hutchings, intertidal in amongst mangroves, sand and reef, AM W.53796, 1 specimen . NORTHERN TERRITORY: NT 319 , Darwin Harbour , Dudley Pt., 12° 24’ 54” S, 130° 49’ E, coll. 18 July 1993, 8 m, coral rubble and algae, AM W.53797, 1 specimen .

Diagnosis. Body densely provided with very numerous, rounded to convoluted dermal glands. Dorsal cirri slender, moderately long, alternating in length in midbody. Compound chaetae bidentate falcigers with short spines on margin. Posterior aciculae straight and distally pointed.

Description. Longest specimen (AM W.53793) 7 mm long, 0.4 mm wide, with 80 chaetigers; single specimen from NT longer (AM W.53797), 10 mm long for 78 chaetigers. Body without colour pattern, but provided dorsally with dark, dense dermal glands, also some ventral glands, rounded, some convoluted in a few specimens ( Fig. 13A, B ); dorsal dermal glands appearing on proventricular segments on some specimens, but on all segments in other specimens ( Fig. 13A ).Antennae, tentacular cirri and dorsal cirri with dark inclusions ( Fig. 13A, B ). Prostomium oval; four eyes in trapezoidal arrangement. Palps broad, similar in length to prostomium or shorter ( Fig. 13A ). Median antenna arising between posterior eyes, thick, long, with about 16–25 articles, distinctly longer than combined length of prostomium and palps; lateral antennae shorter than median one, with about 12–18 articles. Peristomium similar to subsequent segments, short; becoming longer gradually posteriorly ( Fig. 13A ). Dorsal tentacular cirri similar in length to lateral antenna, with about 17–26 articles; ventral tentacular cirri shorter than dorsal ones, with 10–17 articles. Dorsal cirri tapered, with coiled inclusions inside articles, alternating long cirri similar in length to body width or slightly shorter, with about 20–30 articles, and short cirri, with about 14–20 articles, in midbody; dorsal cirri dorsally coiled over dorsum, more markedly in longer ones ( Fig. 13A, B ). Parapodial lobes distinctly bilobed ( Fig. 13A, B ). Ventral parapodial cirri digitiform, shorter than parapodial lobes. Compound chaetae with short bidentate falcigers, blades with proximal tooth slightly smaller than or similar in size to distal one, and short to moderate spines on margin ( Fig. 13C, D, E ); some shafts with few, short subdistal spines, smooth on posterior segments, especially in ventral-most chaetae, being thicker ventrally posteriorly. Anterior parapodia each with about 10–14 compound chaetae, with blades 24 μm long above, 17 μm long below ( Fig. 13C ); midbody parapodia with 8– 11 compound chaetae each, blades similar to anterior ones, more markedly bidentate ( Fig. 13D ); posterior parapodia with 3–6 compound chaetae each, blades all similar, strongly bidentate, wide and short, 20 μm long above, 15 μm long below ( Fig. 13E ). Dorsal simple chaetae on posterior parapodia, apparently unidentate, with a minute distal notch, and few, short subdistal spines ( Fig. 13F ). Ventral simple chaetae on posterior-most segments only, smooth, bidentate ( Fig. 13G ). Anterior parapodia with three slender aciculae each ( Fig. 13H ), becoming progressively fewer in number and larger in size, only two in each midbody parapodia, one straight and pointed, and other distally blunt ( Fig. 13I ), and finally one solitary acicula in each posterior parapodia, straight and distally pointed, slightly protruding beyond parapodial lobes ( Fig. 13J ). Pharynx extending through about seven segments; pharyngeal tooth on anterior margin of pharynx. Proventricle through 5–6 segments, with about 33 muscle cell rows. Pygidium with two anal cirri, with up to 22 articles, and a median stylus.

Remarks. Syllis pharobroomensis is characterized by having numerous and densely distributed glands on dorsum and compound falcigers with short, bidentate blades. These dermal glands are quite unusual in the genus (see Remarks of S. imajimai n. sp., above). The specimen from the NT is markedly longer than those from WA, with more numerous articles on the antennae and dorsal cirri and compound chaetae more elongated.

Habitat. Dead corals covered by algae, algae. Intertidal and sublittoral.

Distribution. Australia (WA, NT).

Figures

FIGURE 13. Syllis pharobroomensis (Hartmann-Schröder, 1979). AM W.53795. A, anterior end, dorsal view. B, midbody segments, dorsal view. C, falcigers, anterior parapodium. D, falcigers, midbody parapodium. E, falcigers, posterior parapodium. F, dorsal simple chaeta. G, ventral simple chaeta. H, aciculae, anterior parapodium. I, aciculae, midbody parapodium. J, acicula, posterior parapodium. Scale. A, B: 0.2 mm. C–J: 20 µm.