Branchiosyllis exilis (Gravier, 1900)

Linero-Arana, Ildefonso & Diaz Diaz, Oscarn, 2011, Syllidae (Annelida, Polychaeta) from the Caribbean coast of Venezuela, ZooKeys 117, pp. 1-28 : 10

Branchiosyllis exilis (Gravier, 1900) Figs 3.8-3.9

Syllis (Typosyllis) exilis Gravier 1900:160, pl. 10, fig. 19.

Branchiosyllis exilis , Westheide 1974:60, fig. 26 A–H.– Uebelacker 1984:105-107, fig. 100 a–f.– San Martín 1991:233.- San Martín and Bone 2001:614.- San Martín 2003:332-336, figs. 184-185.

Material examined.

BMIL197, (1); (9), BMIL297, (9); BMIL498, (8); BMPL197, (7); BMPL398, (16), all specimens associated with Chondrila nucula ; BMIL498, (11); (22); BMPL197, (5); BMPL398, (6), all specimens associated with Aplysina fistularis , 1-3 m depth; BMPL197, (13); BMIL498, (14); BMPL197, (6), all specimens associated with Ircinia felix , 1-2 m depth.

Description.

Length to 17.6 mm,width 1.2 mm. Body with up to 68 chaetigers. Prostomium with a pair of anterior small eyes and two posterior pairs of lentigerous eyes in trapezoidal arrangement. Median antenna with 15-21 articles; lateral antennae with 12-15 articles. Palps stout, rounded, fused basally. Dorsal tentacular cirri with 19-23 articles, ventral ones with 10-13 articles. Anterior dorsal cirri alternating longer, with 22-38 articles, and shorter, with 17-31 articles. Length and number of articles diminishing posteriorly. Dorsal compound falcigers bidentate (Fig. 3.8), ventral falcigers bidentate in anterior chaetigers, falcate in middle and posterior chaetigers (Fig. 3.9). Pharynx extending through 7 chaetigers. Proventriculus extending through 9-12 chaetigers, with 39-48 rows of muscle cells. Pygidium with a pair of anal cirri with 13-21 articles.

Distribution.

Circumtropical, Mediterranean, Baleares and Chafarinas Island (Spain), and Venezuela.