Spirobranchus latiscapus Marenzeller 1885

Spirobranchus latiscapus (Marenzeller, 1885)

(Fig. 29A, B)

Pomatostegus latiscapus Marenzeller, 1885: 218 –219, pl. 4, fig. 5 [South Japan, 183 m; description].

Pomatoceros auritubus Moore & Bush, 1904: 174 –175, pl. 11 fig. 20, pl. 12, figs 33–37 [Suruga Bay, Japan, 82 m; description]. Spirobranchus latiscapus. — Fauvel 1936: 89 [Setozaki, Shirahama, Japan; diagnosis]; Imajma & Hartman 1964: 272 –274 [Japan;

diagnosis]; Bailey-Brock 1972: 405–406, fig. 1a–d [Hawaii]; Imajima 1976b: 137–138 [Tanega-shima, Southwest Japan]; Yang

& Sun 1988: 314–315, fig. 2F–G [South China Sea]; Sun & Yang 2001a: 197–198, fig. 7G–N [northwest of South China Sea].? Spirobranchus sinensis Wu & Chen, 1981b: 247 –248, fig. 1 [South China Sea, 28 m; see Remarks].

Material examined. AM W.201802 (2), Yonge Reef, 14°35'S, 145°37'E, shell of Nautilus, 300 m, coll. M. Wells, Nov 1985, det. H. ten Hove; AM W.201837, Carter Reef, off Lizard Island, 14°40'S, 145°28'E, 20–30 m, coll. P. Hutchings, 10 Mar 1986, det. H. ten Hove.

Diagnosis. Operculum with 1–5 (3–7) calcareous diabolo-like tiers, decreasing in size distally, with flat to conical tip. Tube: colour shades of reddish/orange (colour may be lost in preservation), triangular, with one large keel and a pair of lower lateral keels, with or without paired rows of pits at sides when attached, free parts often hexangular. Peduncle with long (2/3rd to 4/5th of length) wings, with entire edge (no processes).

Remarks. Because Spirobranchus latiscapus has a confusing synonymy, we have only given the most likely synonyms/references. Being originally decribed from Southern Japan, the nominal taxon subsequently has been reported from areas as distant as Gulf of Suez to New Zealand, from diving depths in tropical seas to temperate New Zealand, down to almost 200 m, an unlikely distribution. Pillai (2009: 165, 170–174, 184–190) split the nominal taxon in 5 species, reinstating and redescribing Sp. maldivensis Pixell, 1913 from the Maldives and Gulf of Oman, and describing 3 new species: Sp. murrayi from the Gulf of Oman, Sp. tenhovei from Tasmania and Sp. zelandicus from New Zealand, all formerly labelled Sp. latiscapus. From New South Wales he described Sp. zibrowii, also similar in operculum and tube. Spirobranchus latiscapus is the only taxon with a rose-red tube, as shown by our specimen AM W.201837 as well. All other nominal taxa have orange to caramel, to white or even bluish tubes. Furthermore, Sp. sinensis Wu & Chen, 1981b (247–248, fig. 1) is very similar if not the same, the “distinctive character” of chitinous spines on the operculum in the latter being remnants of epibiontic Hydrozoa (cf. Bouillon 1974). The complex should be revised.

Distribution. South Japan to tropical Australia; usually off shore, in deeper water.