Syllis edensis Hartmann-Schröder, 1989 n

Álvarez-Campos, Patricia, Riesgo, Ana, Hutchings, Pat & Martín, Guillermo San, 2015, The genus Syllis Savigny in Lamarck, 1818 (Annelida, Syllidae) from Australia. Molecular analysis and re-description of some poorly-known species, Zootaxa 4052 (2), pp. 297-331 : 312-315

Syllis edensis Hartmann-Schröder, 1989 n . comb.

Figures 7 , 8

Typosyllis (Typosyllis) edensis Hartmann-Schröder, 1989: 22 , Figs 20–23; 1990: 46. Typosyllis edensis .— Licher 1999: 147, Fig. 65.

Material examined. Type specimens. Typosyllis (Typosyllis) edensis . AUSTRALIA. NEW SOUTH WALES. Eden, Quarantine Bay, algae on rocks, intertidal, 2 Jan 1976, 2 paratypes ( ZMH P- 19664).

Non-type specimens. AUSTRALIA. NEW SOUTH WALES. Maclean, 29°27'S, 153°12'E, 18 Jan 1976, coll. & id. G. Hartmann-Schröder, 5 specimens (HMZ P- 20173). North Kianinny Gutter, Tathra, 36°44'04"S, 149°59'12"E, alga Pterocladia lucida , 5 m depth, 12 Feb 2003, 1 specimen mounted for SEM (AM W42546.001). Newport Beach, 33°39'S, 151°19'E, intertidal, Corallina sp. in rock pools, 22 Jul 2005, 1 specimen (AM W46288). Boat Harbour, south of Port Stephens, 32°46'S, 152°06'E, 1–2 m depth, from Galeolaria sp. tubes, 14 Mar 2006, 1 specimen (AM W46286).

Morphologicaly similar species. Syllis truncata Haswell, 1920 . PHILIPPINES, Maricaban Island, Tingloy, Sepok Point, 13°38'56"N, 120°56'35"E, coral rubble, 9 m depth, 15 May 2011, Hearst Philippine Biodiversity Expedition, 2009, 1 specimen ( CASIZ 187002). Syllis gerlachi ( Hartmann-Schröder, 1960) . SPAIN. Cabo de Gata, Almería, 36°46'N, 2°14'E, Posidonia oceanica rizomes, 2 m depth, 26 Mar 1986, 1 specimen ( MNCN 16.01/8406). Syllis pulvinata ( Langerhans, 1881) . SPAIN. Denia, Valencia, 38°50'N, 6°24'E, 26 Nov 1997, 6 specimens (16.01/ 8838). Syllis rosea ( Langerhans, 1879) . SPAIN. Cabrera Island, 39°09'N, 2°56'E, 1 Jul 1979, 1 specimen ( MNCN 16.01/7027).

Description. Longest complete examined specimen 13 mm long, 0.3 mm wide, with 88 segments. Body elongated, slender, without colour pattern ( Figs 7 A, 8A–B). Prostomium wider than long, with two pairs of red eyes in trapezoidal arrangement ( Figs 7 A, 8A–B). Median antenna inserted on middle of prostomium, longer than combined length of prostomium and palps, with 15–17 articles; lateral antennae shorter, inserted on anterior margin of prostomium, with 12–13 articles ( Figs 7 A, 8B). Triangular palps longer than prostomium. Nuchal organs as two ciliary bands between prostomium and peristomium ( Fig. 8 C). Peristomium slightly shorter than subsequent segments ( Figs 7 A, 8B), with a minute band of pores on the midline ( Fig. 8 D). Dorsal tentacular cirri longer than antennae, with 15 articles, ventral ones shorter, with 10 articles. Dorsal cirri, alternating long (about 20 articles) and short (14–15 articles) on midbody and posterior segments ( Figs 7 A, 8B). All chaetigers with morphologically similar heterogomph falciger chaetae, with 1–2 pseudospiniger chaetae with bidentate blades, distal tooth slightly larger than proximal one, distally blunt spines on margin ( Figs 7 B–C, 8F–I). Five to six chaetae on anterior and midbody parapodia and 3–4 on posterior ones with distinctly shorter blades, bidentate, short spines on margin; blades of chaetae throughout with dorsoventral gradation in length (75–50 µm on anterior chaetigers, 22–11 µm on midbody and posterior ones) ( Figs 7 B–C, 8F–H). Posteriormost chaetae shorter and wider than anterior ones ( Fig. 8 H–I). Dorsal simple chaetae on posterior parapodia only, distally truncate, with few spines on margin ( Figs 7 D, 8I). Ventral simple chaetae not seen. Anterior parapodia with two aciculae each, one distally blunt and one distally curved; posterior segments with only one distally curved in right angle acicula per parapodium ( Fig. 7 E). Pharynx longer than proventricle, through 12–14 segments; pharyngeal tooth on anterior margin, margin surrounded by crown of 11 soft papillae ( Figs 7 A, 8E). Proventricle extending for 4–6 segments, with about 22 rows of muscle cells ( Figs 7 A, 8A).

Reproduction. According to Hartmann-Schröder (1989) this species develops cephalous stolons with two pairs of eyes and lateral articulated antennae.

Remarks. The most similar species to Syllis edensis n. comb. are Syllis truncata Haswell, 1920 , S. rosea ( Langerhans, 1879) , S. pulvinata ( Langerhans, 1881) and S. gerlachi ( Hartmann-Schröder, 1960) . All of them share the same type of stolon and the morphology of the dorsal simple chaetae and of the aciculae, but they differ in the length of the blades, that are shorter than those of S. edensis n. comb. (see Licher 1999, San Martín 2003). The type material of S. edensis n. comb. also has a longer proventricle (through 8 segments, according to Hartmann- Schröder 1989) than our specimens (4–6 segments), but this difference can be explained by the larger size of the type specimens and the degree of contraction after preservation, since all other characters coincided with those in the other material.

Habitat. Algae, Galeolaria spp. tubes.

Distribution. Australia (New South Wales).

Figures

FIGURE 7. Syllis edensis (Hartmann-Schröder, 1989) n. comb. (AM W 41625). A, anterior end, dorsal view. B, pseudospiniger chaeta, midbody. C, falciger chaetae, midbody parapodium. D, dorsal simple chaeta, posterior parapodium. E, acicula, posterior parapodium. Scale: A, 0.1 mm; B – E, 20 µm.

FIGURE 8. Syllis edensis (Hartmann-Schröder, 1989) n. comb. (AM W 42546). A, anterior end, dorsal view. Scanning Electron Micrographs: B, anterior end, dorsal view; C, nuchal organs; D, detail of band of pores on midline of peristomium. E, pharynx with crown of papillae, ventral view. F, compound chaetae, anterior parapodium; G, compound chaetae, midbody parapodium; H, compound chaetae, posterior parapodium; I, dorsal simple chaeta and falcigers, posterior parapodium.