Eusyllis lamelligera Marion & Bobretzky, 1875

San Martin, G & Hutchings, PA, 2006, Eusyllinae (Polychaeta: Syllidae) from Australia with the Description of a New Genus and Fifteen New Species, Records of the Australian Museum 58, pp. 257-370 : 278-280

Eusyllis lamelligera Marion & Bobretzky, 1875

Figs 15A–J, 16A–F

Eusyllis lamelligera Marion & Bobretzky, 1875: 33 , pl. 3, figs. 9A–C.— Fauvel, 1923: 294, Fig. 113.—San Martín, 2003: 117, figs 54, 55.

Eusyllis dentata Hartmann-Schröder, 1990: 50 , figs 13–16.

Eusyllis habei Imajima, 1966: 97 , text-fig. 31a–k.

Material examined. AUSTRALIA: NEW SOUTH WALES: N side of Bannister Head , N of Ulladulla, 35°19.15'S 150°29.12'E, grey sponge from top of boulder, 18 m, coll. K. Attwood, 6 May 1997, 1 ( AM W28960) ; SW of Bowen Is., Jervis Bay , 35°07.49'S 150°45.77'E, small white sponge with pink lobes, from seagrass bed, 7 m, coll. P. Serov & G.D.F. Wilson, 8 Dec 1993, several ( AM W28416) ; SW of Bowen Is., Jervis Bay , 35°07.49'S 150°45.77'E, rock on sandy bottom covered in bryozoa & polychaetes, 7 m, coll. P. Serov & G.D.F. Wilson, 8 Dec 1993, few ( AM W28415) ; Montagu Roadstead, Jervis Bay , 35°02.2'S 150°46.0'E, unvegetated sediment, 12 m, coll. P.A. Hutchings & party, 6 Jun 1990, 1 ( AM W28231) ; NW corner of Bowen Is., Jervis Bay , 35°06.81'S 150°46.11'E, dense bryozoans under rock ledge, 13 m, coll. P. Serov & G.D.F. Wilson, 8 Dec 1993, several ( AM W28959) ; Darling Road, near anchorages, Jervis Bay , 35°7.3'S 150°44.1'E, 18 m, coll. P.A. Hutchings, 23 Jan 1973, 2 ( AM W28437) ; Taupo Seamount, Tasman Sea , 33°16.85'S 156°09.15'E, limestone & sand bottom, 244 m, coll. J.K. Lowry & party, on RV “Franklin”, 2 May 1989, 5 on SEM stub ( AM W28877) ; Taupo Seamount, Tasman Sea , 33°16.85'S 156°09.15'E, limestone & sand bottom, 244 m, coll. J.K. Lowry & party on RV “Franklin”, 2 May 1989, many ( AM W28927) ; Reef flat, near wreck “Yoshin Maru Iwaki”, Elizabeth Reef, Tasman Sea , 29°55.8'S 159°01.3'E, algae, 0.5 m, coll. Elizabeth & Middleton Reefs Expedition, 1987, 14 Dec 1987, several ( AM W28928) . TASMANIA: Woodchip Jetty, Spring Bay, Triabunna , 42°30'S 147°55'E, muddy bottom, 4 m, coll. D. Cropp, Nov 1982, 1 ( AM W199178 ) . SOUTH AUSTRALIA: Billy Lights Point, Port Lincoln , 34°45'S 135°53'E, stone washings from sheltered intertidal rocks, coll. I. Loch, 15 Feb 1985, 1 ( AM W28929) . WESTERN AUSTRALIA: Goss Passage, Beacon Is. 28°25.5'S 113°47'E, dead plates of Acropora coral covered in coralline algae, 24 m, P.A. Hutchings, 21 May 1994, 1 ( AM W28374) ; N end of Long Is. 28°27.9'S 113°46.3'E, dead coral substrate covered in coralline & brown algae, 5.5 m, coll. C. Bryce, 22 May 1994, several ( AM W28961) .

Additional material examined Eusyllis dentata AUSTRALIA: NEW SOUTH WALES: Angourie Point, south of Yamba, 29°29'S 153°22'E algae, intertidal, holotype ( HZM P-19963), 8 paratypes ( HZM P-19964), 1 ( HZM P-203313). Eusyllis habei JAPAN: Bos Peninsula, Hubara Port, 1, coll. E. Nishi. Eusyllis lamelligera SPAIN: off Punta Jovo, W. W Menorca, Balearic Is. 10 m, algae 43°40.27'– 43°40.06'N 5°13.36'– 5°14.35'E, 6 ( MNCNM 8675); NW Cabo de Lastres, Asturias, Cantabrian Sea, NE Atlantic, 39°49.66'– 39°47.64'N 2°40.78'– 2°38.71'E, 146 m, 8 ( MNCNM 8688).

Description. Complete specimen 6.3 mm long, 0.5 mm wide, with 50 chaetigers. Prostomium semi-circular; 4 eyes in open trapezoidal arrangement and 2 anterior eyespots. Median antenna more than twice combined length of prostomium and palps, inserted on middle of prostomium, lateral antennae shorter than median antenna, inserted in front of anterior eyes, near anterior margin ( Fig. 15A). Palps broad, similar in length to prostomium ( Fig. 15A). Nuchal organs with distinct ciliation, extending to posterior margin of prostomium ( Figs 15A, 16A). Peristomium similar to subsequent segments; dorsal tentacular cirri long and slender, more than twice as long as body width, ventral tentacular cirri about third length of dorsal cirri. Antennae, tentacular and dorsal cirri smooth, long, slender, distally tapered ( Fig. 15A), sometimes rugose to weakly pseudoarticulate ( Fig. 16B). Dorsal cirri of chaetiger 1 longer than dorsal tentacular cirri, remaining dorsal cirri irregularly alternating long, and short cirri, long cirri much longer than body width, and short ones, slightly shorter than body width ( Fig. 15A). Ventral cirri of chaetiger 1 enlarged, flattened leaf-like; following ones conical ( Figs 15B, 16B); ventral cirri with minute pores ( Fig. 16D). Lateral tufts of cilia on each segment ( Fig. 16C). Compound chaetae heterogomph, with subdistal spines on shafts and bidentate blades, both teeth similar in size, well separated and rounded margin between both teeth, and fine spines on margin ( Figs. 15D,F,G, 16E,F). Anterior parapodia with about 20–25 compound chaetae, with strong dorsoventral gradation in size of blades within fascicle, about 40 µm in length dorsally, 21 µm in length ventrally. Progressively along body, number of compound chaetae per parapodium decreases, to 13–15 on midbody, 10 on posterior parapodia, with thicker shafts and blades, with less marked dorsoventral gradation in length of blades; on midbody, blades about 35 µm in length dorsally, 22 µm in length ventrally, and 30 µm in length dorsally, and 15 µm in length ventrally on posterior parapodia ( Fig. 15D,F,G). Dorsal simple chaetae on posterior parapodia, slender, bidentate, both teeth similar, with short spines on margin ( Fig. 15I). Ventral simple chaetae on far posterior parapodia, similar to dorsal simple chaetae, but larger and teeth well separated ( Fig. 15J). Anterior parapodia with 2 aciculae, one distally knobbed with acute tip, other with tricuspid tip, with lateral ones poorly developed ( Fig. 15E); medium and posterior parapodia each with single acicula, distinctly tricuspid ( Fig. 15H). Pharynx through about 7 segments; pharyngeal tooth, conical, on anterior margin; trepan variable, ranging from few small teeth present to distinct incomplete crown of up to 24 teeth ( Figs 15C, 16B).

Remarks. This species is characterized by having enlarged, flattened leaf-like ventral cirri on chaetiger 1, tricuspid aciculae, and compound chaetae with bidentate blades, with both teeth of similar size and well separated by rounded margin. The Australian specimens were described as Eusyllis dentata by Hartmann-Schröder (1990); and these were examined and they are indistinguishable from Mediterranean specimens of Eusyllis lamelligera . This species has been reported from a wide range of habitats and depths and material should be re-examined and a molecular study would be useful to confirm if this is a widely distributed species or a suite of sibling species.

Eusyllis habei Imajima, 1966 , from Japan, is also similar according to the description and may represent the same species according to Imajima (1966). The material examined from Bos Peninsula, Japan appears to be similar to specimens of E. lamelligera from the Mediterranean and also to material from the Atlantic and Australia.

Habitat. Occurring in a wide variety of substrates and depths, intertidally to depths greater than 500 m.