Haplosyllis crassicirrata Aguado, San Martín & Nishi, 2006

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 : 6-10

Haplosyllis crassicirrata Aguado, San Martín & Nishi, 2006

Figs 4A–G , 5A–F

Haplosyllis crassicirrata Aguado et al. 2006: 10 , fig. 1–2.— Lattig & Martin, 2009: 16 , fig. 10.

Examined material. AUSTRALIA: NEW SOUTH WALES. 250 specimens AM W36621 (plus 4 specimens mounted for SEM), Jervis Bay, half way along west side of Bowen Island , 35º06'55''S 150º45'55''E, grey sponge with orange flesh, large oscular chamber, 8 m, coll . G. Wilson and P. Serov , 7 Dec 1993 .

Comparative material: Japan, Boso Peninsula. Holotype ( MNCN 16.01 /10135); 2 Paratypes ( MNCN 16.01 /10136).

Description. Body fragile, translucent, small, 2 – 3 mm long, for 20–26 segments (14–18 in juveniles or smaller specimens), 0.4–0.8 mm wide excluding parapodia, ( Figs 4A, E ; 5A ), widest at proventricle level; pale yellow when preserved, with orange marks in dorsal cirri and anterior or posterior ends (probably from host sponge, not seen in all specimens); granulose dorsally. Prostomium subpentagonal to oval similar in width and length ( Fig. 4A, E ), with two pairs of small red eyes in trapezoidal arrangement. Median antennae inserted on middle of prostomium, between eyes (9–21 articles); lateral antennae on anterior margin (6–13 articles). Palps long, broadly triangular, fused at their bases but separated all along their length, with sensory organs as rows of cilia on ventral upper side ( Fig. 5C ). Pharynx orange, 0.18–0.35 mm long, extending through 3–4 segments; with large anterior tooth surrounded by crown of 10 soft papillae and inner ring of cilia ( Fig. 5B ); sometimes with trepan of about 10 small triangular teeth; upper ventral side of papillae with groups of cilia making up the sensory organs. Proventricle cylindrical, dark-brown, 0.25–0.32 mm long, 0.2–0.6 mm wide, extending through 2–4 segments, with 22–26 muscle cell rows ( Fig. 4A, E ). Peristomium well defined, shorter than subsequent segments. Dorsal tentacular cirri (10–13 articles), twice as long as ventral ones. First three dorsal cirri always slender, similar to antennae and tentacular cirri; subsequent ones broad ( Fig. 4A ) or slender ( Fig. 4E ). Anterior dorsal cirri long, with a well-defined length pattern: first long (exceed body width, with 12–20 articles); second short (4–9 articles), third and fourth progressively longer (5–12 and 7–13 articles respectively); fifth short (3–12 articles), six long (7–12). Median cirri long, all equal in length (6–14 articles), longest cirri exceed body width, gradually decreasing in length toward posterior end (1–5 articles) ( Fig. 4B ). Ventral cirri digitiform, anterior ones similar or shorter than parapodial lobes ( Fig. 4C , 5D ), median cirri and posterior ones small ( Fig. 4D ). Chaetae all bidentate, 2–4 per parapodia, equal throughout, anterior ones slightly smaller; LMF similar in length to SW; MJP short, curved; denticles of US of MF absent or very short; apical teeth equal in length, long, well separated ( Figs 4F , 5E–F ). All parapodia with one acicula, with curved, upwards-directed tip ( Fig. 4G ).

Reproduction. The reproductive bodies of Haplosyllis crassicirrata are cephalic stolons. About 15 females with 26–31 segments have the last 12–14 segments modified into reproductive bodies, with cirri smooth or with 2–3 articles. Cirri from non-reproductive segments were slender, some with broad articles at their tips.

Distribution. AUSTRALIA (New South Wales); JAPAN (Boso Peninsula).

Remarks. The studied specimens showed different cirri shapes, from all broad to almost all slender (but still a few broad). As the types were juveniles having most cirri broad and the studied specimens have almost all cirri slender, we suggest that the differences in the presence of broad cirri are linked to the ontogeny. In turn, the chaetae and aciculae were identical in all studied specimens, this being a more robust character for the identification of H. crassicirrata .

The presence of the ciliated sensory organs on palps and pharyngeal papillae is here reported for the first time in Haplosyllis crassicirrata .

Figures

FIGURE 4. Haplosyllis crassicirrata. A—anterior end, dorsal view, observe broad cirri; B—posterior end, ventral view. C—posterior parapodium; D—anterior parapodium, third chaetiger; E—anterior end, dorsal view, observe the slender cirri; F—posterior chaetae; G—posterior acicula. Scale: A, B, E = 200 µm; C–D = 92 µm; F–G = 10 µm. A–D specimen with broad cirri (AM W36621); E–G specimen with slender cirri (AM W36621).

FIGURE 5. SEM micrographs of Haplosyllis crassicirrata. A—whole body, lateral view, specimen with both, broad and slender cirri (arrows); B—anterior end showing pharynx, ventral view; C—ciliated sensory organs, upper-ventral side of pharyngeal papillae; D—anterior parapodium; E—anterior chaeta, first chaetiger; F—median chaeta. White arrows of A pointing a broad (down) and non-broad cirrus (up). Scale: A = 500 µm; B = 50 µm; C = 3 µm; D = 100 µm; E–F = 5 µm. Two specimens (AM W36621).