Haplosyllis uncinigera ( Grube, 1878 )

Lattig, Patricia, Martin, Daniel & Martín, Guillermo San, 2010, Syllinae (Syllidae: Polychaeta) from Australia. Part 4. The genus Haplosyllis Langerhans, 1879, Zootaxa 2552 (1), pp. 1-36 : 33-34

Haplosyllis uncinigera ( Grube, 1878)

Figs 22A–K, 23A–F

Syllis uncinigera Grube, 1878: 113–114 .

Haplosyllis hainanensis Sun, 1996: 19–20 , fig. 2 a–f.― Sun & Yang, 2004: 317–318, figs 185 a–h.― Lattig & Martin, 2009: 32–34, fig. 23.

? Syllis violaceoflava Grube, 1878: 115–116 Pl. 7, fig. 3.

Examined material. AUSTRALIA, WESTERN AUSTRALIA: 1 specimen AM W36624, reef south of Lucas Island, Brunswick Bay, Kimberley region , 15°16'S 124°29'E, 2 m, coll. P.A. Hutchings, 24 July 1988 . 2 specimens AM W36625 (plus 1 specimen mounted for SEM), south side of Long Reef, Kimberley region , 14º01'S 125º44'E, 20 m, 18 July 1988, coll. P.A. Hutchings. Haplosyllis cf. uncinigera : 1 specimen AM W36626, northeast entrance to Goss Passage, Beacon Island , 28º27'54''S 113º46'42''E, 33 m, underneath isolated boulders embedded in coral sand, 25 May 1994, coll. P.A. Hutchings.

Comparative material examined. South China Sea: Haplosyllis hainanensis 1 SYNTYPE SMF 10856; 1 specimen SMF 10855; 3 specimens SMF 10857; 2 specimens SMF 10858 . Philippines: Haplosyllis uncinigera HOLOTYPE ZMB F.1977.

Description. Body robust, long, 1.8–2 cm long, for 100 segments (Figs 22A, 23A), widest at proventricular region, gradually tapering towards posterior end. Two specimens with dark brown pigmented palps, prostomium and anterior segments; pale yellow from proventricular region to posterior end (Fig. 22A). Prostomium subpentagonal, with two pairs of small red eyes in trapezoidal arrangement. Median antennae inserted on middle of prostomium (16–21 articles); lateral antennae on anterior prostomial margin (11–15 articles). Palps long, broadly triangular, fused at their bases. Sensory organs of palps not seen. Nuchal organs as two lateral ciliated grooves between prostomium and peristomium. Pharynx very long, extending through 12 segments, with large anterior tooth, crown of 10–13 soft papillae and inner ring of cilia ( Fig. 23B ); upper ventral side of papillae with groups of cilia making up the sensory organs. Proventricle cylindrical, extending through about 11 segments, dark brown, with 58–84 muscle cell rows. Peristomium well defined, shorter than subsequent segments. Dorsal tentacular cirri (18–20 articles) longer than ventral ones. Dorsal cirri similar to antennae and tentacular cirri, long, slender, whip-shaped. Anterior dorsal cirri slightly longer than medium and posterior ones; first long (24–28 articles); second short (8–16 articles), third and fourth long (23 and 22– 28 articles, respectively), fifth intermediate (14–21 articles), sixth long (20–25 articles); thereafter, slightly alternating with long (20–29 articles) and slightly shorter (10–18 articles), gradually decreasing in length towards posterior end. Posterior cirri relatively short (6–14 articles). Ventral cirri digitiform, anterior ones broad, as long as parapodial lobes (Fig. 22B), median and posterior ones, slender (Fig. 22C). Anterior chaetae bidentate, 2–3 per parapodia, with apical teeth long, similar in length; LMF shorter than SW, with short denticles on US of MF (Figs 22D; 23C–D). Median and posterior chaetae of two different sizes, long and short, each parapodia with 1–2 long chaetae and one short (Figs 22G–H; 23E–F); long chaetae with narrow angle between apical teeth, distal one very small, sometimes giving a unidentate appearance (Figs 22G; 23F), with LMF similar in length to SW; MJP straight and relatively long; US of MF with few, short denticles, sometimes eroded. Short chaetae markedly bidentate, with wide angle between apical teeth, proximal tooth shorter than distal one; MJP short (Figs 22H; 23E). Aciculae of three types: straight (Fig. 22J); with upwarddirected curved tips (Fig. 22I), and (more rarely) with curved tips bent at 90º (Fig. 22K); 4–5 in anterior parapodia, 3–4 in median and posterior regions. Pygidium with two (broken) anal cirri.

Reproduction. Not known.

Remarks. The Australian specimens are identified as H. uncinigera due to their long pharynx and proventricle, the presence of two different chaetal shapes on each parapodia (long, with unidentate appearance and short, markedly bidentate). Two specimens also had a brown pigment pattern as reported by Sun (1996) for the Chinese population. Accordingly, the presence of this pigmentation seems to be a variable character, being more frequent in long and robust specimens ( Lattig & Martin 2009).

Distribution. AUSTRALIA (Western Australia); PHILIPPINES (Bohol); SOUTH CHINA SEA (Nansha and Hainan Islands).

FIGUE 22. Haplosyllis uncinigera . A—anterior end, dorsal view; B—anterior parapodium; C—posterior parapodium; D—anterior chaeta; E and F—anterior aciculae; G—long chaeta with small distal tooth, midbody; H—small chaeta with bidentate tip; I, J, K—posterior aciculae. Scale: A = 500 µm; B, C = 200 µm; D–K = 20 µm. (AM W36624).

Figures

FIGURE 23. SEM micrographs of Haplosyllis uncinigera. A—anterior end, lateral view; B—pharynx showing soft papillae and ring of cilia; C—anterior chaetae, small one markedly bidentate, larger one broken at the tip; D—detail of small anterior chaeta; E—median chaetae, small one markedly bidentate, long one with unidentate appearance; F— longer chaetae, median body. Scale: A = 500 mm; B = 100 µm; C = 10 µm; D = 5 µm; E = 20 µm; F = 30 µm. (AM W36625)