Haplosyllis ingensicola Lattig, Martin & Aguado, 2010

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 : 17-19

Haplosyllis ingensicola Lattig, Martin & Aguado, 2010

Figs 10A–H, 11A–D

Haplosyllis ingensicola Lattig et al. 2010: 792-794 , figs 3-5.

Examined material. AUSTRALIA: WESTERN AUSTRALIA. 4 specimens AM W36618 , Goss Passage, Beacon Island , 28º25'30''S 113º47'E, 8 m, dead plates of Acropora , covered in coralline algae, coll . P. A. Hutchings, 22 May 1994. 60 specimens AM W36619 ( 2 specimens mounted for SEM), Lafoutaine Island, Kimberleys , 14º10'S 125º47'E, 15 m, coll . P. A. Hutchings, 19 July 1988. 105 specimens AM W36620 , Lafoutaine Island, Kimberleys , 14º10'S 125º47'E, 15 m, coll . P. A. Hutchings , 19 July 1988 .

Description. Body fragile, translucent, medium to long sized, 7–13 mm long for 37–53 segments ( 25–35 in juveniles), widest at proventricle segments, gradually tapering towards posterior end ( Fig. 11A); with dark brown pigment pattern on palps, prostomium and anterior segments (even preserved), disappearing at proventricle level, becoming pale cream. Prostomium subpentagonal, wider than long, with two pairs of small red eyes in trapezoidal arrangement ( Fig. 10A). Median antenna inserted on middle of prostomium, twice as long (29–58 articles) as lateral ones (13–23 articles); lateral antennae inserted on anterior margin of prostomium. Palps slightly longer than prostomium, broadly triangular, fused at their bases but separated all along their length ( Fig. 10A). Sensory organs of ventral side of palps, pharyngeal papillae and nuchal organs not seen. Pharynx pale orange, extending through 6–8 segments; with large anterior tooth, surrounded by crown of about 10 soft papillae and inner ring of cilia. Proventricle cylindrical, pale brown, extending through 3–6 segments, with 33–43 muscle cell rows ( Fig. 10A). Peristomium well defined, shorter than subsequent segments. Antennae, tentacular cirri and dorsal cirri long, slender, whip shaped. Dorsal tentacular cirri twice as long (21–33 articles) as ventral ones. Anterior dorsal cirri very long (some twice as long as body width), with a well-defined length pattern: first longer than remaining ones (32–63 articles), second shorter (as long as body width, for 12–20 articles), third and fourth intermediate, longer than second (19–24 and 32–42 articles, respectively), fifth shorter (14–24 articles), sixth intermediate (24–42) ( Fig. 10A). Median cirri alternating long (17–41) and short (11–18), slightly decreasing in length towards posterior end ( Fig. 10B). Ventral cirri digitiform, anterior ones longer and wider than median and posterior ones, slightly longer than parapodial lobes. Chaetae all bidentate, 2–3 per parapodia, apical teeth long, distal one slightly shorter than proximal tooth; anterior chaetae ( Figs 10C; 11B) with 2–3 rows of short spines on US of MF; LMF similar in length than SW; MJP short and curved. Median and posterior chaetae ( Figs 10D, E; 11C–D) with short, eroded spines on US of MF; LMF longer than SW; MJP straight. Anterior parapodia with 1–2 aciculae, straight ( Fig. 10G), and with curved tip bent at 90º ( Fig. 10F); one acicula in median and posterior parapodia, broader than chaetae, with curved tip bent at 90º ( Fig. 10H). Pygidium with two long anal cirri (13–15 articles).

Reproduction. Not known.

Remarks. Haplosyllis ingensicola is easily identified by the whip-shaped cirri, longer than body width, the brown pigment pattern on anterior region and the median and posterior broad acicula with curved tip. The apparently cannibalistic behaviour reported for the Indonesian population ( Lattig et al. 2010), has not been observed within the Australian one.

Distribution. AUSTRALIA ( Western Australia); INDONESIA ( Java and Sulawesi).