Syllis albanyensis ( Hartmann-Schröder, 1984 ) Hartmann-Schroder, 1984

Martín, Guillermo San, Álvarez-Campos, Patricia & Hutchings, Pat, 2017, The genus Syllis Savigny in Lamarck, 1818 (Annelida: Syllidae: Syllinae) from Australia (second part): four new species and re-description of twelve previously described species, Zootaxa 4237 (2), pp. 201-243 : 203-205

Syllis albanyensis ( Hartmann-Schröder, 1984) , n. comb.

Figure 1

Typosyllis (Typosyllis) albanyensis Hartmann-Schröder, 1984: 16 , figs 16, 17, 18, 19; 1986: 37; 1987: 32; 1989: 19. Typosyllis albanyensis . Licher 1999: 145, fig. 65.

Material examined. AUSTRALIA. WESTERN AUSTRALIA: Typosyllis (Typosyllis) albanyensis ; Frenchman Bay, Albany (Western Australia); algae, sand and detritus, 21 Nov 1975 ; coll. and id. Hartmann-Schröder; 3 paratypes ( ZMH P-17880). NEW SOUTH WALES: 100 m north-west of Split Solitary Island , NSW 697, 30 ° 14' S, 153° 10' 48" E, AM W.48570 , 1 specimen, coll. 7 March 1992; Manta Reef, North West Solitary Island, NSW 481, 30 ° 1' 30" S, 153° 16' 30" E, AM W.48571 , 2 specimens, coll. 25 June 1992; Esmeralda Cove, Broughton Island, St. 2818, 32° 37' 12" S, 152° 19' E, AM W.48572 , 4 specimens, coll. kelp holdfast, 11 May 1978, by P. Hutchings; Golf Course bommie, 500 m north-east of Ulladulla Head, 35° 20' 28" S, 150° 29' 12" E, NSW 1298, AM W.48568, 1 specimen, coll. 15 m, 2 May 1997; 50 m east of Burrill Rocks , NSW 1278, 35 ° 23' 24" S, 150° 28' 10" E, AM W.48569, 3 specimens, coll. 1 May 1997 .

Comparative material. Typosyllis (Typosyllis) horrockensis Hartmann-Schröder, 1982 , Horrocks (Western Australia), 1 paratype ( ZMH P-16480).

Typosyllis (Typosyllis) pharynxcircumfusata Hartmann-Schröder, 1979 . Broome (Western Australia); Holotype (HMZ P-15471).

Description. Longest complete specimen 6.5 mm long, 0.35 mm wide, with 87 chaetigers. Body relatively thick and short, with wide and short, well-marked segments, especially anteriorly, brownish, without colour pattern. Prostomium rectangular; 4 eyes in tapezoidal arrangement. Palps broad, similar in length to prostomium ( Fig. 1 A). Median antenna arising in middle of prostomium, with about 16–18 articles, almost twice as long as combined length of prostomium and palps; lateral antennae shorter than median one, with 14 articles. Peristomium dorsally shorter than subsequent segments ( Fig. 1 A). Dorsal tentacular cirri similar in length to median antenna, with about 15 articles; ventral tentacular cirri about 2/3 as long as dorsal ones, with 10 articles. Dorsal parapodial cirri relatively thick, shorter than body width, with well marked articles; distinct, large boomerang-shaped; inclusions inside articles of dorsal parapodial cirri, especially from proventricular segments ( Fig. 1 A), alternating long and short, no marked difference of length, with 16/13 articles in midbody ( Fig. 1 A). Parapodia conical ( Fig. 1 A). Ventral parapodial cirri digitiform, shorter than parapodial lobes. Compound chaetae of anterior and midbody segments with 2 dorsalmost chaetae with distinctly longer blades, 32–34 µm long, straight or slightly curved, bidentate with both teeth close, and moderate coarse spines on margins similar ( Fig. 1 B, C) and 6–7 chaetae with shorter blades, 21–13 µm long. more separated teeth, spines on margin not so coarse ( Fig. 1 B, C), and dorsoventral gradation in length; blades shorter from midbody to posterior parapodia ( Fig. 1 D); posterior parapodia with 5 compound chaetae, with blades 19 µm long above, 14 µm long below ( Fig. 1 D); some specimens with chaetae with long blades also present to posterior part of body. Dorsal simple chaetae on posterior parapodia, distally truncate ( Fig. 1 E), sometimes with subdistal and distal short spines ( Hartmann-Schröder 1984; fig. 19). Ventral simple chaetae on far posterior segments, sigmoid, bidentate ( Fig. 1 F). Anterior parapodia with 2–3 slender aciculae each, distally rounded ( Fig. 1 G), reducing to 1 in each midbody and posterior parapodia, distally ending in right angle ( Fig. 1 H, I). Pharynx long, extending through about 11–13 segments; pharyngeal tooth elongated, conical, acute, on anterior margin of pharynx ( Fig. 1 A). Proventricle similar in length to pharynx, through 11–13 segments, with about 27–30 muscle cell rows. Pygidium with 2 anal cirri, with 8–12 articles, and a median stylus.

Remarks. This species is easily recognized by its truncate dorsal simple chaetae, aciculae distally bent in right angle (“foot-like”), compound chaetae moderately long blades, with both teeth very close to each other, and short, thick spines all reaching to the same level, and pharynx and proventricle both long, of similar length. Syllis albanyensis is similar to Syllis erikae (Hartmann-Schröder, 1981) , from Western Australia and redescribed below, but that species is distinctly slender and filiform, with a longer pharynx and shorter proventricle.

Syllis edensis ( Hartmann-Schröder, 1989) , from New South Wales, is also similar, but the dorsal cirri are longer, the blades of the dorsal compound chaetae are longer and more markedly curved, and the proventricle is shorter (see Álvarez-Campos et al. 2015a).

Syllis pulvinata ( Langerhans, 1881) , from the Canary Islands and the Mediterranean Sea, is probably the most similar species. However, there are some small differences in the compound chaetae, having coarser spines on margin in S. pulvinata , and some specimens of that species have 1–2 dorsal glands on the segments immediately posterior to the proventricle ( Langerhans 1881; San Martín 2003); none of the examined specimens of Syllis albanyensis have them. Although the species resemble each other they can be distinguished on the basis of the thickness of spines on the compound chaetae and the presence or absence of the dorsal glands and also by their geographical distribution.

The examined paratype of Typosyllis (Typosyllis) horrockensis Hartmann-Schröder, 1982 is a broken, anterior part (without proventricle), and it is difficult to state the differences with Syllis albanyensis , but they seem to be different species, although probably close, as discussed by Licher (1999).

The Western Australian species Typosyllis pharynxcircumfusata Hartmann-Schröder, 1979 has very similar chaetae, but the dorsal cirri are shorter, tapered, and the proventricle is distinctly shorter; furthermore, that species has a unique structure in the anterior part of body, similar to a spherical cover, surrounding the anterior part of the pharynx (see Hartmann-Schröder 1979), very conspicuous in the holotype.

Finally, Syllis truncata Haswell, 1920 , has similar chaetae, but with shorter blades and also a distinctly shorter proventricle.

Habitat. Associated with kelp holdfasts, algae, sand and detritus.

Distribution. Australia (New South Wales and Western Australia).

Figures

FIGURE 1. Syllis albanyensis (Hartmann-Schröder, 1984), n. comb. (AM W. 48569). A, anterior end, dorsal view. B, compound chaetae, anterior parapodium. C, compound chaetae, midbody parapodium. D, compound chaetae, posterior parapodium. E, dorsal simple chaeta. F, ventral simple chaeta. G, aciculae, anterior parapodium. H, acicula, midbody. I, acicula, posterior parapodium. Scale bars: A: 0.1 mm. B – I: 20 µm.