Trypanosyllis zebra ( Grube, 1860 )

Martín, Guillermo San, Hutchings, Pat & Aguado, María Teresa, 2008, Syllinae (Polychaeta, Syllidae) from Australia. Part. 2. Genera Inermosyllis, Megasyllis n. gen., Opisthosyllis, and Trypanosyllis, Zootaxa 1840, pp. 1-53 : 43-47

Trypanosyllis zebra ( Grube, 1860)

Figs 31F, 32, 33A, B, 34A–F, 35A–F, 36A–F

Syllis zebra Grube, 1860: 86 , pl. 3, fig. 7. Trypanosyllis zebra Langerhans 1879: 556 .- Haswell 1920: 101.- Fauvel 1923: 269, figs 101 a–e.- Day 1967: 256, figs.

12.6. a–b.-San Martín 2003: 311, figs 171–173. Trypanosyllis krohnii Claparède, 1864: 558 , pl. 7, fig. 2. Syllis taeniaformis Haswell, 1885: 741 , pl. 1, figs 4, 5. Trypanosyllis taeniaformis Augener 1913: 230 .- Westheide 1974: 39, figs 16a–d.- Day & Hutchings 1979: 105. Trypanosyllis (Trypanedenta) taeniaformis Imajima & Hartman 1964: 127 , figs 30 h–k.- Imajima 1966b: 239, figs. 45 a–

i.- Hartmann-Schröder 1989: 18. Trypanosyllis richardi Gravier, 1900: 168 , pl. 9, figs 12, 13. Trypanosyllis vittigera Ehlers, 1887: 151 , pl. 40, figs 1–3.- Uebelacker 1984: 30–88, figs 30–81, 82a–h. Parautolytus luzonensis Pillai, 1965: 123 , figs 5E–I, 6A–C.

Material examined. AUSTRALIA, WESTERN AUSTRALIA: Kimberleys, W side of Cassini Island, 13° 57'S, 125° 37'E, low tide, coll. P.A. Hutchings, 18 Jul 1988, 1 ( AM W31406); S side of Long Reef, 14° 01'S, 125° 44'E, 20 m, coll. P.A. Hutchings, 18 Jul 1988, 1 ( AM W31410); Condillac Island, 14° 06'S, 125° 33'E, sand with scattered bommies, 6 m, coll. P.A. Hutchings, 16 Jul 1988, 2 ( AM W31427); Lafontaine Island, 14° 10'S, 125° 47'E, 15 m, coll. P.A. Hutchings, 19 Jul 1988, 1 ( AM W31420); Western Bernouli Island, 15° 00'S, 124° 47'E, intertidal, coll. P.A. Hutchings, 12 Jul 1988, 2 ( AM W31411); Exmouth Gulf, Bundegi Reef, N end of beach, 21° 49'S, 114° 11'E, 2 m, rocky rubble with sediment, brown alga with epiphytic growth, coll. H.E. Stoddart, 4 Jan 1984, 1( AM W31417); Houtman Abrolhos, off S end of Long Island, Beacon Island, 28° 28' 48"S, 113° 46' 18"E, 5 m, dead coral substrate covered in coralline algae, coll. P.A. Hutchings, 25 May 1994, 7 (1 on 2 SEM stubs), ( AM W31423); NE entrance to Goss Passage, Beacon Island, 28° 27' 54"S, 113° 46' 42"E, dead branching staghorn Acropora sp. , 24 m, coralline and brown algae, coll. P.A. Hutchings, 25 May 1994, 1 ( AM W31422); N end of Long Island, Goss Passage, 28° 27' 54"S, 113° 46' 18"E, 6 m, dead coral substrate, covered in coralline algae, coll. C. Bryce, 22 May 1994, 2 ( AM W31418), 2 ( AM W31419), 2 ( AM W31416); Goss Passage, Beacon Island, 28° 25' 30"S, 113° 47'E, 8 m, dead plates of Acropora sp. , covered in coralline algae, coll. P.A. Hutchings, 19 May 1994, 2 ( AM W31409); Goss Passage, Beacon Island,, 28° 25' 30"S, 113° 47'E, 23 m, dead plates of Acropora sp. , covered in coralline algae and sponges, coll. P.A. Hutchings, 19 May 1994, 1 ( AM W31408); Goss Passage, Beacon Island, 28° 25' 30"S, 113° 47'E, 8 m, dead plates of Acropora sp. , covered in coralline algae, coll. P.A. Hutchings, 22 May 1994, 2 ( AM W31424); Cottesloe Beach, 9.5 km W of Perth, 31° 59'S, 115° 45'E, 0.5 m, in calcareous algae and Idanthyrsus worm tubes, coll. H. Paxton, 14 Feb 1970, 1 ( AM W4347); Western Bunbury Harbour, 33° 19' 25"S, 115° 39' 24"E, 12.8 m, coll. L.J.B. Laurenson for Bunbury Ballast Water Project, 27 Mar 1993, 1 ( AM W21954); Warnbro Sound, W of Penguin Island, 32° 18'S, 115° 41'E, 5 m, reef substrate, algae and sponge, coll. P.A. Hutchings, 21 Mar 1993, 2 ( AM W26741). SOUTH AUSTRALIA: Sellick's Beach, N reef, 35° 20'S, 138° 27'E, sievings in Cymodocea , coll. P.A. Hutchings, 16 Mar 1979, 1 ( AM W26353); Elliston Reef, 33° 39'S, 134° 53'E, algae on reef flat at low tide, coll. P.A. Hutchings, 11 Mar 1979, 1 ( AM W26352); Northern Great Australian Bight, 32° 24'S, 133° 30'E, 49 m, coll. P. Symonds on Prawn Survey "Explorer", 23 Aug 1973, 1 ( AM W13627); Port Noarlunga, S Reef, 35° 10'S, 138° 28'E, coll. H. Duyverman, South Australian Fisheries, 10 Jan 1976, 1 ( AM W13620); Kangaroo Island, American River Inlet, 35° 48'S, 137° 46'E, coll. H. Duyverman, 1976, 1 ( AM W14041). TASMANIA: Bruny Island, Fancy Point, 43° 16'S, 147° 19'E, 3 m, coll. Graham Edgar, 10 Nov 1980, 1 ( AM W18190). VICTORIA: Port Phillip Bay, Corio Bay, 38° 06'S, 144° 25' 55"E, 5 m, silty clay, coll. Marine Science Lab - Corio Bay benthic survey, 01 Jul 1987, 1 ( AM W29378); Gabo Island, 37° 34'S, 149° 25'E, 28 m, exposed conditions, coll. S. Shepherd, 17 Feb 1973, 1 ( AM W15645); Gabo Island, 37° 34'S, 149° 25'E, 4.5 m, coll. P.A. Hutchings, 13 Feb 1973, 1 ( AM W15641); Gabo Island, 37° 34'S, 149° 25'E, on vertical face & among Phyllospora sp. , coll. P.A. Hutchings, 15 Feb 1973, 4 ( AM W15642). NEW SOUTH WALES: 150 m east of Burrill Rocks, 35° 23' 25"S, 150° 28' 11"E, 17 m, dead bryozoan encrusted with algae, bryozoa and hydroids, coll. K. Attwood, 1 May 1997, 3 ( AM W31426); Golf Course Bommie, 500 m NE of Ulladulla Head, 35° 20' 29"S, 150° 29' 12"E, 15 m, gravel around base of boulders, coll. P.B. Berents & K. Attwood, 2 May 1997, 1 ( AM W31421); Green Point, Jervis Bay, 35° 01'S, 150° 45' 12"E, 12 m, unvegetated sediment, coll. P.A. Hutchings & party, 27 Feb 1990, 1 ( AM W31407); Port Jackson, 33° 51'S, 151° 16'E, donated by Professor W.A. Haswell, Nov 1919, 3 ( AM W512); Port Jackson, 33° 51'S, 151° 16'E, donated by Professor W.A. Haswell, Nov. 1919, 16 ( AM W486); Manly, Sydney, 33° 48'S, 151° 17'E, under rocks & calcareous algae, at low tide, coll. H. Paxton, 20 Dec 1968, 1 ( AM W4326); Broughton Island, Esmeralda Cove, 32° 37' 12"S, 152° 19'E, kelp holdfast, coll. NSW State Fisheries, 11 May 1978, 2 (1 on SEM stub), ( AM W18517); 50 m W of Split Solitary Island, 30° 14'S, 153° 10' 48"E, 16 m, Herdmania momus , rocks, sponges and ascidians, coll. P.A. Hutchings & C.L. Rose, 07 Mar 1992, 2 ( AM W31415). TASMAN SEA: Taupo Seamount, 33° 16' 51"S, 156° 09' 09"E, 244 m, coll. J.K. Lowry on RV "Franklin", 2 May 1989, 3 ( AM W31412); Reef flat near "Yoshin Maru Iwaki" wreck, Elizabeth Reef, 29° 55' 48"S, 159° 01' 18"E, intertidal, from small heads of Acropora valida , Pocillopora damicornis , coll. J.K. Lowry & R.T. Springthorpe on Elizabeth & Middleton Reefs Expedition 1987, 14 Dec 1987, 5 ( AM W31413). QUEENSLAND: Calliope River, Gladstone, 23° 51'S, 151° 10'E, 8 m, muddy sand, coll. P. Saenger, Nov. 1982, 1 on SEM stub, ( AM W198064). NORTH- ERN TERRITORY. Darwin Harbour, East Point, 12° 24' 36"S, 130° 39' 57"E, 7—10 m, dead coral rubble and algal washings, coll. P.A. Hutchings, 17 Jul 1993, 2 ( AM W31414); Lee Point, 12° 20'S, 130° 53' 48"E, 3 m, dead coral rubble washings, coll. P.A. Hutchings, 11 Jul 1993, 2 ( AM W31425).

Description. Based on large, complete specimen, broken in two pieces, 105 mm long, 2 mm wide, with 260 chaetigers. Body long, dorso-ventrally flattened, ribbon-like, with numerous short and large segments ( Figs 31F, 32, 34A, B), reddish or rose pigment on cirri and on two dorsal bands on each segment ( Fig. 32), more marked anteriorly, disappearing posteriorly, sometimes also red pigment on prostomium; 2–3 transverse rows of minute papillae on each segment ( Fig. 35A, B). Prostomium subtrapezoidal, ( Fig. 32), posteriorly bilobed ( Fig. 34E, F), densely ciliated, covered by most anterior segments when contracted; three ceratophores well marked on anterior margin; median antenna short, with about 20 articles, similar in length or slightly longer than lateral ones, with about 17 articles. Two prostomial lobes or cheeks, with two pairs of eyes in trapezoidal arrangement ( Fig. 32). Palps slightly shorter than prostomium, completely separate, oval. Peristomium smaller than subsequent segments, usually partially or totally covered by chaetiger 1; tentacular cirri longer than antennae, with about 18 articles; slightly longer than ventral ones. Dorsal cirri thick, usually shorter than body width ( Figs 31F, 32), occasionally much longer in similar sized specimens; dorsal cirri of two kinds, long and slightly thicker, dorsally directed ( Figs 32, 34A–D), more strongly pigmented, with about 38 or more articles, alternating with shorter, laterally directed, less pigmented, with less articles. Ventral cirri digitiform, shorter than parapodial lobes ( Fig. 35C). Compound chaetae similar throughout body, about 12–14 per parapodium, with thick shafts and bidentate blades ( Fig. 33A), both teeth similar on long blades ( Fig. 36B–D), proximal smaller than distal on short ones ( Fig. 36E, F), marginal spines short and straight; blades about 77 µm on most dorsal chaetae, 46 µm on most ventral. Aciculae thick, acutely pointed ( Fig. 33B), extending beyond parapodial lobes, 3–4 anteriorly, 2–3 posteriorly. Some specimens with capillary dorsal and ventral simple chaetae on posterior parapodia, slender, smooth, bidentate. Pharynx long, through about 11 segments; pharyngeal armature variable, depending on size of specimens (see Remarks). Proventricle long and slender, similar in length to pharynx ( Figs 32, 35E), with about 40–50 muscle cell rows. Pygidium with 2 anal cirri, shorter than dorsal cirri. Stolons Tetraglene , with eyes developing ventrally; one stolon per atokous individual, posterior end starts to regenerate before detaching stolon ( Fig. 35D).

Remarks. Trypanosyllis zebra is one of the most common littoral species of Syllidae . Within a sample, individuals of different sizes can often be found revealing that some characters seem to be size-dependent. Small specimens are less coloured (or even colourless), with shorter cirri, and a mid-dorsal pharyngeal tooth together with a trepan of 10 teeth and a crown of 10 soft papillae. The relative length of dorsal cirri and the pigmentation increase with size of animal. Medium-size and large specimens lack mid-dorsal pharyngeal tooth, and large specimens have more papillae surrounding the pharyngeal opening, sometimes more than 20 ( Figs 35E, F, 36A). However, there are no enough evidences to support they are not the same species, therefore appearing to be widely distributed or cosmopolitan. However, this should be confirmed by molecular studies.

Habitat. Common in all substrates, including algae, calcareous concretions, sponges, dead corals, bryozoans, hydroids, ascidians, sand, silty clay and gravel; from intertidal to 50 m deep.

Distribution. Cosmopolitan in temperate and tropical seas; Australia (all States).