Syllis setoensis ( Imajima, 1966 )

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 : 321-324

publication ID

https://doi.org/ 10.11646/zootaxa.4052.3.2

publication LSID

lsid:zoobank.org:pub:52083710-01B3-4CF1-A6CE-5A09419F7D25

DOI

https://doi.org/10.5281/zenodo.6112230

persistent identifier

https://treatment.plazi.org/id/03E4CD0F-FFDF-FFD6-9199-FF7FFBC3856C

treatment provided by

Plazi

scientific name

Syllis setoensis ( Imajima, 1966 )
status

 

Syllis setoensis ( Imajima, 1966) View in CoL

Figures 12 View FIGURE 12 , 13 View FIGURE 13

Typosyllis setoensis Imajima, 1966: 284 View in CoL , Fig. 62 A–L.— Licher 1999: 124, Fig. 56 A–F. Syllis setoensis Aguado et al., 2008: 33 View in CoL .

Material examined. Non-type material. AUSTRALIA. WESTERN AUSTRALIA. Woodside Kimberley Survey, 2009–2010: Cassini Island, lower mid-littoral reef platform, 13°57'06"S, 125°37'27"E, 3 m depth, 18 Oct 2010, 1 specimen mounted for SEM (AM W41605.001); Montgomery Reef, mid-littoral lower terrace, 16°01'14"S, 124°09'33"E, coral rubble with Sargassum sp., intertidal, 23 Oct 2009, 1 specimen (AM W42462); Long Reef, mid-littoral lower terrace, 13°49'11"S, 125°46'48"E, coral rubble and algae, intertidal, 23 Oct 2010, 1 specimen (AM W42528); Adele Island, sublittoral fore-reef slope, 15°34'49"S, 123°09'26"E, coral and algae, 12.6 m depth, 18 Oct 2009, 1 specimen (AM W42529). Bush Bay, 30 km south of Carnarvon, 25°10'S, 113°39'E, in algal lumps on shallow sand flats, intertidal, 6 Jan 1984, 1 specimen, (AM W46283). Off south end of Long Island, 28°28'48"S, 113°46'18"E, dead coral and algae, 4–5 m depth, 25 May 1994, 1 specimen (AM W46287). PHILIPPINES. LUZON ISLAND. “Koala Point”, Balayan Bay, 13º41'51"N, 120º49'45"E, coral rubble, 5–16 m depth, 5 Dec 2010, 1 specimen ( MCZ 25418); “Sepok Wall”, between Balayan Bay and Batangas Bay, 13º41'02"N, 120º53'45"E, coral rubble, 6–13 m depth, 10 Dec 2010, 1 specimen ( MNCN 16.01/16870).

Morphologically similar species. Syllis krohni : SPAIN. Nerja, Málaga, calcareous algae, 14 Jun 1983, 1 specimen ( MNCN 16.01/8180). Typosyllis (Typosyllis) krohnii . AUSTRALIA. QUEENSLAND. Heron Island, North Reef, coralline sand, 4 Feb 1976, coll. and id. G. Hartmann-Schröder, 13 specimens ( HZM P- 21006), NEW ZEALAND. Kermadec Biodiscovery Expedition, 2011: Kermadec Islands, Raoul Island, “Fishing Rock” landing, 29°15'03"S, 177°54'12"W, algal turf, 1 m depth, 18 May 2011, 7 specimens (AM W42886).

Description. Longest examined specimen incomplete, 6 mm long, 0.8 mm wide, with 60 chaetigers. Body relatively robust anteriorly, slender from midbody, without colour pattern ( Figs 12 View FIGURE 12 A, 13A–B). Prostomium oval, wider than long, with two pairs of red eyes in trapezoidal arrangement and 2 anterior eyespots ( Figs 12 View FIGURE 12 A, 13A–B). Median antenna inserted on middle of prostomium, between anterior pair of eyes, longer than combined length of prostomium and palps, with 30–32 articles ( Figs 12 View FIGURE 12 A, 13B); lateral antennae shorter, inserted at anterior margin of prostomium, with 25–27 articles (small specimens with fewer articles in antennae and cirri, Fig. 12 View FIGURE 12 A). Palps triangular, longer than prostomium ( Fig. 12 View FIGURE 12 A). Nuchal organs not seen. Peristomium shorter than subsequent segments ( Fig. 12 View FIGURE 12 A), in larger specimens forming a small lobe partly covering posterior part of prostomium ( Fig. 13 View FIGURE 13 B). Dorsal tentacular cirri similar in length to median antenna, with 32–34 articles, ventral ones shorter with 24– 26 articles ( Fig. 12 View FIGURE 12 A). Dorsal cirri of chaetigers 1, 4, 6, 9, 11 distinctly thickened ( Figs 12 View FIGURE 12 A, 13A–C); midbody dorsal cirri alternating long (longer than body width) and short (shorter than body width); long dorsal cirri slightly thicker than short dorsal cirri ( Fig. 12 View FIGURE 12 A). Anterior dorsal cirri (except those of anteriormost chaetigers) with 30–33 articles. Midbody and posterior dorsal cirri shorter, with 23–25 articles. Antennae and tentacular cirri spindleshaped, thicker than dorsal cirri. Anterior and midbody parapodia each with 8–10 bidentate, falciger chaetae. Blades bidentate, with proximal tooth smaller than distal one, with dorsoventral gradation in length (34–21µm on anterior parapodia; 30–20 µm on midbody parapodia), short spines on edge, shafts with short distal spines ( Figs 12 View FIGURE 12 B–C, 13D–E). Posterior parapodia with 8–9 compound chaetae; blades hooked, bidentate, shorter than those of anterior parapodia, almost all similar in length (22 µm dorsalmost, to 20 µm ventralmost), with acute distal tooth, small proximal tooth, and short spines on edge ( Figs 12 View FIGURE 12 D–E, 13F–G); ventralmost chaetae short, some unidentate ( Fig. 12 View FIGURE 12 F–G); shafts of ventralmost posterior compound chaetae smooth, with a marked spur ( Figs 12 View FIGURE 12 E, 13F–G). Four aciculae in each anterior parapodium, one straight, one distally curved and two distally blunt ( Fig. 12 View FIGURE 12 F), decreasing in number to three aciculae in each midbody parapodium, one distally knobbed, one curved at tip and one larger, straight acicula ( Fig. 12 View FIGURE 12 G); posterior parapodia with 1–2 aciculae each, distally pointed, tip slightly oblique ( Fig. 12 View FIGURE 12 H). Pharynx longer than proventricle, extending through 11 segments; conical tooth located on anterior margin. Proventricle through 7 segments with about 57 muscle cell rows ( Fig. 12 View FIGURE 12 A).

Remarks. The morphology of our specimens agreed with that of Licher’s (1999) redescribed paratype material, except for the length of the specimens (up to 26.4 mm long, 110 chaetigers) and the number of aciculae in each anterior parapodium (3 in the specimens revised by Licher (1999), 4 in our study). The most similar species to Syllis setoensis is S. krohni Ehlers 1864 , which has been reported worldwide. Both species are characterized by having distinctly thickened dorsal cirri in some of the anterior segments, and posterior compound chaetae with distinctly enlarged shafts, distally curved spurs, and short, hooked blades. The two species are distinguished by the form of their compound chaetae, mostly unidentate in S. krohni and mostly bidentate in S. setoensis . Furthermore, while S. setoensis lacks any colour pattern, S. krohni has a distinctive colour pattern (see Fauvel 1923; San Martín 2003).

Habitat. Coral rubble, algae.

Distribution. Japan, New Zealand, Australia (Queensland, Western Australia).

MCZ

Museum of Comparative Zoology

MNCN

Museo Nacional de Ciencias Naturales

HZM

Museum of Natural History (Hrvatski Zooloski Muzej)

NEW

University of Newcastle

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Phyllodocida

Family

Syllidae

Genus

Syllis

Loc

Syllis setoensis ( Imajima, 1966 )

Álvarez-Campos, Patricia, Riesgo, Ana, Hutchings, Pat & Martín, Guillermo San 2015
2015
Loc

Typosyllis setoensis

Licher 1999: 124
Imajima 1966: 284
1966
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