Haplosyllis basticola Sardá, Ávila & Paul, 2002

Lattig, Patricia & Martin, Daniel, 2009, A taxonomic revision of the genus Haplosyllis Langerhans, 1887 (Polychaeta: Syllidae: Syllinae), Zootaxa 2220, pp. 1-40 : 11-13

Haplosyllis basticola Sardá, Ávila & Paul, 2002

( Figs 6 A–G, 7A–F)

Haplosyllis basticola Sardá, Ávila & Paul, 2002: 168 –171, fig. 1–2.

Examined material. Micronesia. Island of Guam, 20 Paratypes MNCN 16.01/8439.

Description. Small, fragile body, length 1–4 mm, for 8–25 segments, width 0.15–0.22 mm, excluding parapodia ( Figs 6 A, 7A), widest at proventricle level. Preserved specimens brown-purple, similar to the host sponge. Dorsal pigmentation absent. Small dorsal granules in all body. Prostomium oval to subpentagonal, wider than long, with two pairs of small red eyes in trapezoidal arrangement. Median antenna inserted on medium of prostomium, with 9–17 articles; lateral antennae inserted on anterior margin of prostomium, with 6–10 articles. Palps twice as long as prostomium, broadly triangular, separated all along their length but in close contact at the base, with sensory organs as two ventral upper-lateral rows of cilia and a few more disperse cilia ( Fig. 7 B–D). Nuchal organs not seen. Pharynx orange, extending about 4 segments, anteriorly with triangular tooth, crown of 9–10 soft papillae and an inner ring of cilia. Cilia of papillae not seen. Proventricle brownish, cylindrical, 0.3–0.45 mm long, extending 2–3 segments, width 0.16–0.27 mm, with 23–30 muscular cell-rows ( Fig. 6 A). Peristomium well defined, shorter than subsequent ones. Dorsal tentacular cirri longer than ventral ones (6–13 and 2–5 articles, respectively). Dorsal cirri slender, similar to antennae and tentacular cirri. Anterior dorsal cirri with well defined variation in length: first cirri longer than remaining ones (10–15 articles); second smaller (2–5 articles), third and fourth slightly longer than second (3– 7 and 4–10 articles, respectively), fifth smaller (2–4 articles). After proventricle, cirri short, similar in length (2–5 articles), gradually decreasing to posterior segments, with 2–3 articles or non-articulated ( Fig. 6 B). Ventral cirri digitiform, shorter than parapodial lobes ( Fig. 6 C). Chaetae bidentate, all similar, broad, but anterior ones smaller. LMF similar to SW; MJP curved, short; US of MF without denticles; apical teeth similar in length, distal one slightly shorter, narrow angle between teeth ( Figs 6 D, F, 7E–F). One chaeta per anterior parapodia, one on midbody parapodia (sometimes second one inside parapodium, difficult to see), and two or three on most posterior segments. One stout acicula on all chaetigers, with slightly curved tip, upwards directed ( Fig. 6 E, G).

Reproduction. Both, male and female reproductive bodies have 11–12 chaetigers with a welldistinguishable head and two small antennae ( Sardá et al. 2002).

Host. Strict endosymbiont of the large sponge Ianthella basta (Pallas, 1766) .

Distribution. Guam, Micronesia.

Remarks. The original species description is here complemented by the description of the ciliated sensory organs on palps, and by presence of 1–3 chaetae from midbody parapodia, instead of only one ( Sardá et al. 2002).

Figures

FIGURE 6. Haplosyllis basticola. A—anterior end, dorsal view; B—posterior end, dorsal view; C—anterior parapodia, chaetigers 4 and 5; D—anterior chaeta; E—anterior acicula; F— midbody chaeta; G—midbody acicula. Scale bars: A – B = 200 Μm; C = 97 Μm; D – G = 20 Μm.

FIGURE 7. SEM micrographs of Haplosyllis basticola. A—whole body, lateral view; B—anterior end, ventral view showing palps with rows of cilia; C—upper-ventral side of palps with rows of cilia (indicated by arrow); D—detail of cilia; E—anterior chaeta; F—posterior chaeta. Arrow of B indicates position of ciliated sensory organs of palps. Scale bars: A – B = 250 Μm; C = 10 Μm; D – F = 2.5 Μm.