Syllis boggemanni, Martín, Guillermo San, Álvarez-Campos, Patricia & Hutchings, Pat, 2017

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 : 205-208

Syllis boggemanni n. sp.

Figures 2 , 3

Material examined. AUSTRALIA, WESTERN AUSTRALIA: Kimberleys, Shirley Island , 16° 17' S, 123° 26' E, holotype, AM W.48526, coll. 26 July 1988, by Pat Hutchings.

Description. Holotype incomplete, lacking most posterior segments, 11 mm long, 0.75 mm wide, with 58 chaetigers. Body large, robust, without colour pattern. Prostomium oval; 4 eyes in open trapezoidal arrangement and 2 minute anterior eyespots, difficult to see. Palps somewhat ventrally folded, similar in length to prostomium ( Fig. 2 A). Median antenna arising slightly in front of posterior pair of eyes, with about 30 articles, distinctly longer than combined length of prostomium and palps; lateral antennae much shorter than median one, with 20–22 articles. Peristomium slightly shorter than subsequent segments ( Fig. 2 A). Dorsal tentacular cirri similar in length to median antenna, with about 24 articles; ventral tentacular cirri about half as long as dorsal ones, with 20 smaller articles. Dorsal parapodial cirri elongated, whip-shaped, alternating in midbody long cirri, slightly longer than body width, with about 42–50 articles, and short cirri, somewhat shorter than body width, with about 30 articles ( Fig. 2 A, B); cirrophores well developed, dorsal cirri dark, articles filled up with spiralized inclusions. Parapodia conical, distally bilobed. Ventral parapodial cirri digitiform. Compound chaetae including spiniger-like and falcigers on each parapodium ( Fig. 3 A–F); blades and shafts slender on anterior segments becoming longer gradually from midbody to posterior parapodia ( Fig. 3 A–F). Spiniger-like chaetae with bidentate blades, both teeth similar and close to each other, short spines on margin, except for distalmost 1–2 spines, which reach level of proximal tooth ( Fig. 3 A, C, E). Falcigers with moderate to long spines on margin, especially 2–3 distalmost ones, reaching and even surpassing level of proximal tooth; bidentate, with proximal tooth slightly longer than distal one from midbody parapodia ( Fig. 3 B, D, F). Anterior parapodia each with 4–5 spiniger-like chaetae, blades 87–84 µm long, and numerous falcigers, about 12, with blades 38 µm long above, 30 µm long below ( Fig. 3 A, B); each midbody parapodium with 2 spiniger-like, blades about 90 µm long, and 5–6 falcigers with blades 54 µm long above, 31 µm long below ( Fig. 3 C, D); each posterior parapodium with 1–2 spiniger-like chaetae, blades 107 µm long, and 8 falcigers, with blades 48–50 µm long above, 30–32 µm long below ( Fig. 3 E, F). Dorsal and ventral simple chaetae not seen. Anterior parapodia with 4 slender aciculae ( Fig. 3 G), 3 at midbody parapodia ( Fig. 3 H), and 2 in posterior parapodia, straight, distally pointed, not protrudingfrom parapodial lobes ( Fig. 3 I). Pharynx extending through about 12 segments; pharyngeal tooth on anterior margin of pharynx ( Fig. 2 A). Proventricle long, through 14 segments, with about 58 muscle cell rows. Pygidium unknown.

Remarks. Syllis boggemanni , n. sp. is characterized by its large size, with a long proventricle, and the compound chaetae, including spiniger-like and falcigers; teeth of spiniger-like blades are very close to each other, and teeth of falciger blades are unequal, with proximal tooth longer than distal one in midbody and posterior parapodia. Also, the spines on margin of midbody and posterior falcigers are long, distally curved, with 2–3 distalmost slender and long. Spiniger-like chaetae are very similar to those of Syllis cornuta Rathke, 1843 (from the NE Atlantic and Arctic) but in this species these chaetae lack the distal long spines, and also the falcigers are different, with short spines on margin of blades (see Licher 1999). Among other species with spiniger-like chaetae, S. hyllebergi ( Licher, 1999) (from the Red Sea and Brazil, see Licher 1999; Nogueira & San Martín 2002) and S. silkeae ( Licher, 1999) (from Taiwan) have similar falcigers, but they lack the long distal spines present in S. boggemanni n. sp.; moreover, these species have shorter dorsal cirri. Syllis yallingupensis ( Hartmann-Schröder, 1982) , also from Australia, is similar in having spiniger-like chaetae and falcigers with long distal spines on margin, but there are several other differences (see redescription of this species below). S. lutea (Hartmann- Schröder, 1960) (circumtropical) (see redescription of this species, below), S. jorgei San Martín & López, 2000 (Western Mediterranean), S. glarearia ( Westheide, 1974) (Galápagos Islands) , and other species (see Licher, 1999 and San Martín, 2003) have similar falcigers, but they all lack spiniger-like chaetae. Finally, Syllis pilosa Aguado, San Martín & Nishi, 2008 , from Japan, has shorter dorsal cirri, dorsal ciliary bands, different aciculae and lacks distal spines on chaetae (see Aguado et al. 2008).

Etymology. The species is named in honor of Dr. Markus Böggemann, Osnabrück University, Germany, for his great contribution to the knowledge of some families of polychaetes, among which are the Syllidae .

Habitat. Dead coral substrate in shallow waters.

Distribution. Australia (Western Australia).

Figures

FIGURE 2. Syllis boggemanni, n. sp. (AM W. 48526). A, anterior end, dorsal view. B, dorsal cirri, midbody parapodia. Scale bars: A: 0.4 mm. B: 0.2 mm.

FIGURE 3. Syllis boggemanni, n. sp. (AM W. 48526). A, spiniger-like compound chaetae, anterior parapodium. B, falcigers, anterior parapodium. C, spiniger-like chaeta, midbody parapodium. D, falcigers, midbody parapodium. E, spiniger-like chaeta, posterior parapodium. F, falcigers, posterior parapodium. G, aciculae, anterior parapodium. H, aciculae, midbody parapodium. I, aciculae, posterior parapodium. Scale bars: 20 µm.