Syllis valida Grube, 1857

Martín, Guillermo San, Lucas, Yolanda & Hutchings, Pat, 2024, The genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae: Syllinae) from Australia (Fourth part), Zootaxa 5453 (1), pp. 1-32 : 13

Syllis valida Grube, 1857

Figure 8

Syllis valida Grube, 1857: 183 .

Typosyllis valida .— Licher 1999: 211, fig. 89.

Material examined. AUSTRALIA, WESTERN AUSTRALIA: Kimberley region, St. 33, Coronation Island , 15° 5’ S, 124° 56’ E, coll. P. Hutchings, 15 July 1988, in mangroves at low tide, AM W.29545, 1 specimen .

Description. Incomplete specimen; body long and thick, robust, 10 mm long, 0.26 mm wide, 123 chaetigers, without colour markings, dorsal cirri and laterals of each segment dark with dense groups of glandular, minute, rounded inclusions ( Fig. 8A ). Prostomium oval, two eyes in open trapezoidal arrangement; median antenna inserted between posterior eyes, with about 16 articles, lateral antennae also short, with about 15 articles. Palps robust, similar in length to body width ( Fig. 8A ). Dorsal tentacular cirri similar in length to long dorsal cirri (about 21 articles in midbody); ventral tentacular cirri similar to short dorsal cirri (about 13 articles) ( Fig. 8A ). Dorsal cirri thick, shorter than body width, with many minute granular inclusions. Compound chaetae all similar, blades short, unidentate or very slightly bidentate falcigers with short spines on margin, those of anterior segments more elongated and distally slightly hooked and those of midbody and posterior segments triangular, some almost smooth on margin ( Fig. 8B–D ). Anterior parapodia with 10–12 falcigers ( Fig. 8B ), blades 26–16 µm long; midbody parapodia with 6–7 falcigers ( Fig. 8C ), blades 23–15 µm long; posterior parapodia with 5–6 falcigers, very similar to those of midbody in shape and length of blades ( Fig. 8D ). Dorsal and ventral simple chaetae not seen. Anterior parapodia with 3–4 slender aciculae, pointed or slightly blunt distally ( Fig. 8E ); midbody parapodia with two aciculae, one distally blunt and other acuminate, with short tip ( Fig. 8F ); posterior parapodia with solitary, thick acicula, acuminate with very short tip ( Fig. 8G ).

Remarks. Our specimen agrees very well with the Licher’ description, although he proposed several synonymies that may be doubtful. This species is similar to Syllis armillaris (O. F. Müller, 1771) , a supposedly worldwide species, also present in Australia, but the dorsal cirri are more elongated, with more articles, and the blades of the compound chaetae are more numerous in midbody parapodia.

Habitat. Found in mangroves in Australia.

Distribution. Chile. First report from Australia (WA), although this wide distribution needs to be confirmed by molecular studies.

Figures

FIGURE 8. Syllis valida Grube, 1857. A, anterior end, dorsal view. B, compound chaetae, anterior parapodium. C, compound chaetae, midbody parapodium. D, compound chaetae, posterior parapodium. E, aciculae, anterior parapodium. F, aciculae, midbody parapodium. G, acicula, posterior parapodium. AM W.29545.Scale. A: 0.1 mm. B-G: 20 µm.