Syllis violacea Grube, 1870

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 : 15-18

Syllis violacea Grube, 1870

Figures 9 , 10 , 11

Syllis violacea Grube, 1870: 500 .

Typosyllis violacea . — Licher 1999: 215, fig. 91.

Material examined. AUSTRALIA, NEW SOUTH WALES: MI NSW 3399 , Sydney Harbour, White Bay berth 3, 33° 51’ 46” S, 151° 11’ 0” E, coll. 5 March 2009, by SCUBA 11.8 m, scraping of wharf piles, AM W.54222, 1 specimen .

Description. Body of large size and robust, 21 mm long, almost 1 mm wide, 75 chaetigers. Most anterior segments with two large dorsal transverse rows of dark purple pigment ( Figs 9A, C, D , 10A ), segments becoming pale on subsequent segments and paler from proventricular segments backwards ( Figs 9A, B , 10B ). Prostomium oval, two pairs of red eyes in trapezoidal arrangement. Antennae, tentacular and dorsal cirri colourless, relatively short in relation to size of specimen. Dorsal cirri similar all along body, somewhat longer on anterior segments, alternating in length; long cirri with about 45 articles ( Fig. 11B ), short cirri with about 32 articles ( Fig. 11A ), and marked cirrophore. Parapodial lobes conical, with two marked lobes ( Fig. 11A, B ); prechaetal lobe longer than postchaetal one. Ventral cirri digitiform, longer than parapodial lobes on anterior segments ( Fig. 11A ). Compound chaetae heterogomph falcigers, with distinctly bidentate blades and moderately long, slightly curved spines on margin ( Fig. 11C, D, E ), similar along body and with slight dorsoventral gradation in size, somewhat elongate on anterior parapodia; shafts distally spinose. Anterior parapodia with about 14 chaetae per parapodium, blades 45 µm long above, 37 µm below ( Fig. 11C ); midbody parapodia with 10 chaetae per parapodium, blades 42 µm above, 35 µm below ( Fig. 11D ); posterior parapodia with 10 chaetae per parapodium, blades 36 µm above, 33 µm below ( Fig. 11E ). Dorsal and ventral simple chaetae not seen. Aciculae straight ( Fig. 11 F-H), distally acute; five in anterior parapodia ( Fig. 11F ), reducing to four in midbody parapodia ( Fig. 11G ) and three in posterior parapodia ( Fig. 11H ). Posterior segments apparently regenerating ( Figs 9A , 10B ).

Remarks. This single specimen agrees quite well with the description made by Licher (1999) of S. violacea from the Red Sea, especially in the colour pattern, shape of chaetae and aciculae, but of a larger size. The chaetae of the Australian specimen seem to have somewhat longer spines on blades margin, but this difference is small. The specimen is very fragile; for this reason, we decided not to dissect it to examine the pharynx and proventricle. This identification needs to be confirmed by molecular studies.

Habitat. In mangroves.

Distribution. Red Sea. Australia (NSW). First record from Australia.

Figures

FIGURE 9. Syllis violacea Grube, 1870. A, complete specimen, latero-dorsal view. B, anterior end, dorsal view. C, anterior end, lateral view. D, detail of prostomium and most anterior segments. AM W.54222. (No scales).

FIGURE 10. Syllis violacea Grube, 1870. A, detail of anterior end, latero-dorsal view. B, detail of posterior end. AM W.54222. (No scales).

FIGURE 11. Syllis violacea Grube, 1870.A, anterior parapodium, lateral view. B, posterior parapodium, C, compound chaetae, anterior parapodium. D, compound chaetae, midbody parapodium. E, compound chaetae, posterior parapodium. F, aciculae, anterior parapodium. G, aciculae, midbody parapodium. H, aciculae, posterior parapodium.AM W.54222. Scale. A, B: 0.2 mm. C-H: 20 µm.