Syllis augeneri Haswell, 1920

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 : 255-257

Syllis augeneri Haswell, 1920

Figure 2

Syllis (Typosyllis) augeneri Haswell, 1920: 98 , pl. 11, Figs 19 –22.— Aguado et al. 2008: 21 , fig. 8.

Material examined. AUSTRALIA, NEW SOUTH WALES: Split Solitary , 30° 15’S, 153°10’ 30” E, coll. 23 June 1992, 16.6 m, AM W.53783, 4 specimens. Boat Harbour, south of Port Stephens, 32° 46’ 59” S, 152° 06’ E, coll. 14 March 2006, 1 m in amongst Galeolaria, AM W. 53787. Newport , 33° 39’S, 33° 39’S, coll. 28 April 2005, in intertidal rock pools, AM W.32034, 2 specimens. NSW 3397 , Sydney Harbour, east side of Cockatoo Island, 33° 50’ 53” S, 151° 10’ 30” E, coll. 5 March 2009, 4 m on SCUBA, scraping on pontoon, AM W.53785, 1 specimen. Fairlight, Port Jackson , 33° 48’ S, 151° 16’ 30” E, coll. 19 Feb 2006, C. Fraser & M. Capa, 1 m, balanoid barnacles and sponges, AM W.37695, 2 specimens . WESTERN AUSTRALIA: WA 362, Cape Range National Park, inshore limestone reef off Neds Camp, 21° 59’ S, 113° 55’ E, coll. 02 Jan 1984, 1 m, AM W.53786, 9 specimens . NORTHERN TERRITORY: NT339, Darwin Harbour, Lee Point , 12° 20’ S, 12° 20’ S, coll. 16 July 1993, 3 m, on SCUBA, coral rubble, AM W.29548, 3 specimens .

Additional material examined 1 syntype AM W.505, Australia, New South Wales, Port Jackson , 33º51’S, 151º16’E .

Diagnosis. Midbody dorsal cirri moderately long; antennae tentacular and anterior dorsal cirri somewhat longer. Compound chaetae of two kinds, few dorsal ones with elongated falcigers and remaining chaetae with distinctly shorter, finely bidentate blades. Posterior aciculae acuminate.

Description. Longest complete specimen, 9 mm long, 0.45 mm wide, with 85 chaetigers. Prostomium oval, wider than long, with two pairs of eyes in trapezoidal arrangement, two eyespots usually indistinct ( Fig. 2A ). Antennae all of similar length, slightly longer than combined length of prostomium and palps together. Median antenna between posterior eyes, with about 16–18 articles; lateral antennae inserted in front of anterior eyes, with 15–16 articles. Palps broad, triangular, slightly longer than prostomium, fused at base, with distinct median groove. Peristomium shorter than subsequent segments, with two pairs of tentacular cirri ( Fig. 2A ). Dorsal tentacular cirri slightly longer than lateral antennae, with about 18 articles, ventral ones with 10–11 articles. Dorsal cirri relatively short, shorter or similar in length to body width and small differences of length between long and short cirri; in midbody, long cirri with about 18 articles and short ones with about 13 articles ( Fig. 2A ). Ventral cirri digitiform, inserted proximally. Compound chaetae including per parapodium few dorsal chaetae with elongated, bidentate blades ( Fig. 2B, D, F ), and some chaetae with distinctly shorter, bidentate blades, and dorso-ventral gradation in length ( Fig. 2C, E, G ). Anterior parapodia each with 3–4 long-bladed chaetae, blades 30–36 μm long ( Fig. 2B ), and 8–10 chaetae with shorter blades 22–23 μm long above, 14 μm below ( Fig. 2C ); distal tip of long blades curved, with proximal tooth small and close to distal one and short spines on edge ( Fig. 2B ); remaining blades with short proximal tooth and moderately long spines on margin ( Fig. 2C ). Midbody chaetigers with two compound long-bladed chaetae, similar to those of anterior parapodia, but longer (50 μm long) ( Fig. 2D ) and about eight chaetae similar to those of anterior parapodia, 28 μm long above, 18 μm below ( Fig. 2E ). Posterior parapodia each with one long-bladed chaeta (sometimes two, and lacking in most posterior parapodia), about 45 μm long ( Fig. 2F ), and six compound bidentate chaetae of similar sizes and shape to those of midbody ( Fig. 2G ). Dorsal simple chaetae slender, slightly bidentate ( Fig. 2H ), only on posterior parapodia. Ventral simple chaetae on most posterior parapodia only, very slightly bidentate ( Fig. 2I ). Anterior parapodia each with 2–3 slender aciculae ( Fig. 2J ), reducing to two on midbody parapodia, one subdistally inflated, acuminate, and other pointed ( Fig. 2K ), and solitary on posterior parapodia, acuminate ( Fig. 2L ). Pygidium with two long anal cirri, each with about 20 articles, and one short median stylus. Pharynx long, extending through 8–11 segments; tooth conical, on anterior margin. Proventricle extending through eight segments (up to 14 when body contracted, Fig. 2A ), with 30–35 muscle cell rows.

Remarks. Syllis augeneri is characterized by having relatively short dorsal cirri and compound chaetae which includes a few dorsal ones with elongated blades, but not as long as to be considered as spiniger-like chaetae, and other falcigers with dorso-ventral gradation in length of blades. The distal tooth of long-bladed chaetae is curved, somewhat rounded, with short proximal tooth, close to distal one.

Aguado et al. (2008) examined one syntype from Port Jackson, NSW, and concluded that the single, incomplete examined specimen from Indonesia belongs to this species; although there are some discrepancies between that description and the syntype from Australia, but this could be due to differences in size or maturity.

Habitat. Sand and shells, amongst serpulids and other encrusting organisms, rock pools, inside limestone rocks, coral rubble. Intertidal and shallow substrates.

Distribution. Australia (NSW, WA). Indonesia.

Figures

FIGURE 2. Syllis augeneri Haswell, 1920. AM W.32040. A, anterior end, dorsal view. B, long-bladed compound chaeta, anterior parapodium. C, falcigers, anterior parapodium. D, long-bladed compound chaeta, midbody. E, falcigers, midbody. F, long-bladed compound chaeta, posterior parapodium. G, falcigers, anterior parapodium. H, dorsal simple chaeta. I, ventral simple chaeta. J, aciculae, anterior parapodium. K, aciculae, midbody parapodium. L, acicula, posterior parapodium. Scale. A: 0.2 mm. B–I: 20 µm.

FIGURE 19. Syllis thylacine n. sp. Holotype, AM W.53916. A, anterior end, dorsal view. B, falcigers, anterior parapodium. C, falcigers, midbody parapodium. D, falcigers, posterior parapodium. E, dorsal simple chaeta, midbody parapodium. F, dorsal simple chaeta, posterior parapodium. G, ventral simple chaeta.H, aciculae, anterior parapodium.I, acicula, midbody parapodium. J, acicula, posterior parapodium. Scale. A: 0.2 mm. B–J: 20 µm.