Hydroides albiceps Grube 1870

Hydroides albiceps (Grube, 1870)

(Fig. 2)

Serpula (Eupomatus) albiceps Grube, 1870: 520 –521 [Red Sea].

Eupomatus albiceps. — Willey 1905: 312, pl. 7, fig. 180A [Sri Lanka]; Hartman 1954: fig. 641 [Marshall Islands]; Reish 1968: 228 [Marshall Islands].

Hydroides albiceps. — Fauvel 1953: 460, fig. 241d, e [Sri Lanka]; Pillai 1960: 12 [Sri Lanka]; 1971: 112–113 [same]; Straughan 1967b: 220, fig. 8m [Qld, Australia]; Imajima 1976a: 234 –235 [diagnosis, Japan]; 1976b: 133–135, fig. 8a–v [Tanegashima, Japan]; 1978: 53–54 [Izu Islands, Japan]; 1979: 168 [Honshu, Japan]; 1982: 44 [Micronesia]; Mak 1982: 601 –602 [Hong Kong]; Day & Hutchings 1979: 143 [Qld; name in checklist]; Imajima & ten Hove 1984: 43–44 [Truk Islands, Ponape and Majuro Atoll; Shark Bay, WA, Australia; Gulf of Thailand, Indonesia, Samoa]; 1986: 5 [Solomon Islands]; Vine & Bailey-Brock 1984: 139, fig. 2K [Sudan, Red Sea]; Yang & Sun 1988: 311, fig. 150 F–G [South China Sea]; Nishi 1993a: 12, table 1 [Ryukyu Islands; reproduction]; Meng et al. 1994: 47 [Hainan, South China Sea]; Wang & Huang 1993: 7 [Hong Kong; fouling]; Ishaq & Mustaquim 1996: 164 –166, fig. 2 [Pakistan]; Hassan 1998: 50 [Red Sea, figure]; Mohan et al. 1997: 351, 354–355, fig. 10 [India; fouling]; Fiege & Sun 1999: 112 –114 [Hainan Island, China]; Sun & Yang 2000: 117 –118, fig. 1A–G [same]; ten Hove & Ben-Eliahu 2005: 129 –132, 134, 135, 137, 143–145 [opercular development; Seychelles, Red Sea, Philippines, Samoa, Qld, Australia]; ten Hove & Kupriyanova 2009: 52 [name only]; Sun et al. 2012a: 7, figs 3A–B, 4A–H [Hong Kong]; Bailey-Brock et al. 2012: 969 [Enewetak, Marshall Islands]; Sun et al. 2015: 10 –14, fig. 2 [WA, NT, Qld, Australia].

Hydroides minax (not Grube).— Gibbs 1971: 203 [Solomon Islands].

Hydroides spiratubus Pillai, 2009: 128 –131 [Kimberley, WA].

Material examined. AM W.20155 (2), Turtle Beach, lagoon, 14°40'S, 145°28'E, coll. G. Anderson, 22 Jun 1982; MAGNT W025510, off Casuarina Beach, lagoon of Patch Reef, 14°40'48''S, 145°26'42''E, coral rubble, 2 m, coll. N. Bruce, 15 Apr 2008.

Diagnosis. Opercular verticil with 6–13 spines, curved outward, with rectangular to clavate tips, without any accessory spinules. Dorsal verticil spine vesicular, consisting of a bulbous median part, and two latero-dorsal more or less triangular (seen from the dorsal side) outpockets; the three parts vary considerably in relative size. Funnel with 14–31 clavate to bottle-shaped chitinized radii, bluntly rounded in juveniles, base of funnel not chitinized. Grooves separating radii extending 1/2 of funnel length (Fig. 2).

Remarks. The species is most similar to Hydroides trivesiculosa Straughan, 1967b. According to Sun et al. 2015, H. albiceps differs from H. trivesiculosa in the size and shape of the dorsal verticil spine. H. trivesiculosa has an exceptionally large vesicular dorsal verticil spine which is more than 5 times longer than the smaller verticil spines. The lateral outpockets of the dorsal verticil spine are straight in H. albiceps, while those of H. trivesiculosa are larger and curved ventrally.

Distribution. Red Sea, widely distributed in the Indo-West Pacific.