Galathowenia quelis Capa, Parapar & Hutchings, 2012

Parapar, Julio & Moreira, Juan, 2015, The Oweniidae (Annelida; Polychaeta) from Lizard Island (Great Barrier Reef, Australia) with the description of two new species of Owenia Delle Chiaje, 1844, Zootaxa 4019 (1), pp. 604-620 : 607-610

Galathowenia quelis Capa, Parapar & Hutchings, 2012

( Figs 1 B, 2–5)

Material examined. Thirty-two specimens in 24 samples plus a number of empty tubes. AM W.41287 (20), sand, 6.5 m; AM W.41322, MI QLD 2144 (10+ fixed in EtOH), sand, 6.5 m; AM W.43729 (4), 3.6 m; AM W.43897, MI QLD 2334 (3); AM W.43899, MI QLD 2333, e.t.; AM W.44106, MI QLD 2345, fixed in EtOH; AM W.44108, MI QLD 2355; AM W.44110, MI QLD 2340 (3); AM W.44116, MI QLD 2347; AM W.44239, MI QLD 2374, e.t.; AM W.44240, MI QLD 2373 (4); AM W.44242, MI QLD 2367, e.t.; AM W.44245, MI QLD 2363, e.t.; AM W.44295, MI QLD 2376 (4); AM W.44297, MI QLD 2373; AM W.44549, MI QLD 2391; AM W.44698, MI QLD 2414; AM W.44700, MI QLD 2415; AM W.44703, MI QLD 2419; AM W.45128, MI QLD 2432; AM W.45132, MI QLD 2439, fixed in EtOH; AM W.45134, MI QLD 2433; AM W.45135, MI QLD 2437, fixed in EtOH; AM W.47383, MI QLD 2440 (2 fixed in EtOH); AM W.45400, MI QLD 2441; AM W.45401, MI QLD 2441, fixed in EtOH; AM W.45406, MI QLD 2443, e.t.; AM W.45410, MI QLD 2444; AM W.45466, MI QLD 2445; AM W.45860 (6), sand, 3 m; AM W.45863 (50), sand, 3 m; AM W.45866 (7), medium to fine sediment, 18 m; AM W.45867 (7), sand, 3 m; AM W.45869 (6), 3 m; AM W.45870 (10), sand, 3m; AM W.45872 (25), medium sand, 3 m; AM W.45874 (7), sand, 3 m; AM W.45907 (5), organic material, 1.8 m; AM W.45908 (4), 3 m; AM W.45909, 3 m; AM W.45910 (2), medium sand, 3 m; AM W.45911 (2), seagrasses, 21.2 m; AM W.45914, fine sediment, 10.6 m; AM W.45915, medium sand, 3 m; AM W.45916, fine sediment, 10.6 m; AM W.45920 (3), medium sand, 3 m; AM W.45921 (3), medium sand, 3 m; AM W.45922, fragments, filamentous algae; AM W.45923 (10), medium sand, 3 m; AM W.45911 (2), seagrass, 21.2 m; AM W.45912 (4), organic material, 1.8 m; AM W.45913, coarse to medium sand, 4.5 m; AM W.45918 (2), coarse to medium sand, 3 m; AM W.45919, fine sticky sediment, 12 m; AM W.47384, sand, 3 m, on SEM stub; AM W.47385, sand, 6.5 m, on SEM stub; AM W.47386, muddy sand, 5 m, on SEM stub.

Remarks. Specimens collected were small sized but still showing clearly the most diagnostic characters of G. quelis : body slender and thread-like, about 0.2 mm wide, with eyespots, and anterior region with three uniramous segments being the second chaetiger (u2) twice as long as u1 and u3 (RLTS: 1–2–1) ( Figs 3 A, 4A–B, D). The terminal mouth extends midventrally as an elongated slit which is profusely ciliated ( Fig. 4 C); its length is quite variable (cfr. Fig. 4 B, D–E). The ventral surface of some specimens has a rough appearance which is likely due to the presence of glandular cells ( Fig. 4 F). The size of the first biramous segments is as follows: b1 about 1.5 of all anterior uniramous segments (u1–u3) ( Fig. 3 A); b2 is the longest segment (near b1); b3 is about 3/4 of b2. Several specimens were regenerating both the anterior and posterior ends, while others were not; in the latter it could be distinguished the characteristic two blunt lobes located each side of anus ( Figs 3 C–D, 5D–E). These lobes are particularly visible ventrally ( Figs 3 C, 5D) and less marked dorsally, showing a low rim ( Fig. 5 E) as referred by Capa et al. (2012; Fig. 4 K–M). Fine ornamentation of notochaetae (scale covering of capillary chaetae; Fig. 5 A) and neuropodial uncini (bifid uncinus with two nearly equally convex teeth, one offset slightly higher then the other and arranged in an oblique row; Fig. 5 B–C) agrees with that of the original description ( Capa et al. 2012). The tube is composed by a thin secreted layer encrusted with sand grains ( Fig. 5 F). Unlike Capa et al. (2012), no parasitic copepods were observed in the Lizard Island specimens.

Habitat. From intertidal to 25 m depth, mostly on sandy and muddy sand, widely distributed in the studied area ( Fig. 1 B).

Distribution. Galathowenia quelis shows a wide distribution across Australia, along the eastern coast in Botany Bay to the North up to Brisbane, being also present in the Arafura Sea ( Capa et al. 2012). This record in Lizard Island confirms its presence in the Coral Sea north of Cairns.

Figures

FIGURE 1. Map of the study area showing collecting sites of Galathowenia and Owenia species described or reported in this work. In (B − D) arrows facing to cross-shelf sampling sites: EI = Eagle Island; NDI = North Direction Island. Dots refer to material collected during LI Workshop held in August 2013; stars refer to AM material; white star refers to type locality of O. picta n. sp.

FIGURE 3. Galathowenia quelis Capa et al., 2012 (AM W. 45866). A. Anterior end, ventral view; B. Posterior end, dorsal view; C. Posterior end, ventral view.

FIGURE 4. Galathowenia quelis Capa et al., 2012 SEM micrographs (AM W. 47386, AM W. 41287 and AM W. 45867). A – B. Anterior end, latero-ventral view; C. Detail of mouth ciliature of (B); D. anterior end, latero-ventral view; E. Detail of mouth ciliature of (D); F. Detail of body surface.

FIGURE 5. Galathowenia quelis Capa et al., 2012. SEM micrographs (AM W. 47386, AM W. 41287 and AM W. 45867). A. Scale covering of thoracic notopodial capillary chaetae; B – C. Abdominal neuropodial hooks, oblique view; D. Posterior region, ventral view; E. Posterior region, dorsal view; F. Tube covering.