Syllis cf. nigrescens Grube, 1878

Martín, Guillermo San, Lucas, Yolanda & Hutchings, Pat, 2023, The genus Syllis Savigny in Lamarck, 1881 (Annelida: Syllidae: Syllinae) from Australia (Part 3): new species and redescription of previously described species, Zootaxa 5230 (3), pp. 251-295 : 269-270

Syllis cf. nigrescens Grube, 1878

Figure 9

Syllis nigrescens Grube, 1878: 124 .

Typosyllis nigrescens .— Licher 1999: 267, fig. 112.

Typosyllis (Typosyllis) ornata Hartmann-Schröder, 1965a: 101 , Figs 25–27. (?)

Typosyllis ornata Hartman 1966: 201 (?).

Material examined. AUSTRALIA, NEW SOUTH WALES: SE of Bate Bay , T3-141 , 34° 06’ 48” S, 151° 1’ E, coll. 29 Oct 1900, 65–70 m, Smith McIntyre grab, AM W.53792, 4 specimens .

Description. All specimens in poor condition. One complete specimen 15 mm long, 0.2 mm wide, 108 chaetigers. Body slender, filiform. Almost all appendages lost; only few dorsal cirri present, short, with 16–13 articles. Compound chaetae falcigers; blades bidentate, proximal tooth small and short spines on margin ( Fig. 9B ); anterior parapodia with about 16 chaetae, diminishing progressively to 6–8 on posterior parapodia, blades all similar, 23–20 µm long. Anterior parapodia each with three thick, distally blunt aciculae, two on midbody and posterior parapodia, thicker than those of anterior parapodia, one distinctly thicker than rest ( Fig. 9D ), straight, distally pointed, and single on most posterior parapodia, very thick, protruding beyond parapodial lobes ( Fig. 9E ). Dorsal simple chaetae in posterior parapodia, slightly curved, unidentate ( Fig. 9A ). Ventral simple chaetae on most posterior parapodia, smooth, distally bidentate with smooth proximal tooth ( Fig. 9C ).

Remarks. These NSW specimens are in poor condition, so we cannot provide a more detailed description or a diagnosis. Compound chaetae and aciculae agree quite well with Licher’s description and drawings, based on a syntype, and we believe that our specimens may correspond with this species. However, both Grube’s and Licher’s descriptions state that the dorsal cirri are longer than the few ones present on our specimens, and so this must be considered a tentative identification.

Licher (1999) considered the species Typosyllis ornata described by Hartmann-Schröder (1965a) from Hawaii to be synonymous with Syllis nigrescens . However, we suggest that they may represent two different species, since the chaetae in Hartmann-Schröder’s description are distinctly bidentate. A detailed molecular study is needed to confirm this identification.

Habitat. Sediments, 65–70 m.

Distribution. Philippines. Hawaii (?). Australia (NSW) (?).

Figures

FIGURE 9. Syllis cf. nigrescens Grube, 1878. AM W.53792. A, dorsal simple chaeta. B, falcigers, midbody. C, ventral simple chaeta. D, aciculae, anterior parapodium. E, acicula, posterior parapodium. Scale. 20 µm.