Laevistrombus vanikorensis Quoy & Gaimard 1834

Laevistrombus vanikorensis Quoy & Gaimard, 1834

Figure 8

Synonymy

1834, Strombus vanikorensis Quoy & Gaimard, p. 73, no. 8, pl. 51, figs. 7 to 9.

= Strombus canarium var. vanikorensis Duclos, 1844, in Chenu, pl. 7, figs. 4 and 5.

= Strombus vanikorensis Quoy—Reeve 1851, spc. 46.

= Strombus (Strombus) canarium vanikorensis Horst & Schepman—Adam & Leloup 1938, p. 110.

= Strombus vanicorensis Quoy—Tryon 1885, p. 146.

= Strombus vanicorensis Tryon—Wagner & Abbott 1978, p. 09–658.

Strombus canarium Linnaeus—Kiener 1843, p. 33, pl. 29, fig. 1a. Allan 1950, p. 99, pl. 17, fig. 2. Rippingale & McMichael 1961, p. 56, pl. 5, fig. 15. Wilson & Gillett 1971, p. 40, pl. 18, fig. 1. Deas 1971, unnumbered page/plate, fig. 5. Jansen 1996, p. 17, figs. 53b and c.

= Strombus (Strombus) canarium Linnaeus — Tryon 1885, pp. 110 and 136, pl. 2, fig. 18.

= Strombus (Gallinula) canarium Linnaeus — Chenu 1859, p. 256, figs. 1590 and 1591. Melvill & Standen 1899, p. 165.

= Canarium (Labiostrombus) canarium Linnaeus—Solem 1958, p. 220. = Strombus (Laevistrombus) canarium Linnaeus — Abbott 1960, p. 36, pl. 17, fig. 15. Wilson & Gillett 1979, p. 73, pl. 14, fig. 1. = Laevistrombus canarium Linnaeus—Maxwell et al. 2017, p. 133. Laevistrombus canarium guidoi Man in ‘T Veld & de Turck—Liverani 2013, p. 24, pl. 143, fig. 2.

Type material. We hereby select the first syntype in the Muséum National d’Histoire Naturelle, Paris: Collection: Molluscs: MNHN-IM-2000-32459 (two syntypes), size 55.3 mm as lectotype of L. vanikorensis Quoy & Gaimard, 1834. The other syntype, with the writing “Vanikoro” in the mouth, becomes the paralectotype.

Type locality. The type locality for L. vanikorensis is Vanikoro Island, Solomon Islands.

Original description. “Strombus, testa obovata, laevi, alba, lineis castaneis confertissimis longitudinalibus maxime flexuosis picta; spira conic-elongata, mucronata; apertura alba; labro crasso dilatato” (Quoy & Gaimard 1834, p. 73) Strombus, shell ovate with a narrow basal end, smooth, white, with many longitudinal winding chestnut lines, spire elongated and conical, mucronate, aperture white, lip thickened and calloused (Translation SM).

“On the first impression, one mistakes this species for Strombus canarium; but that species differs by its consistently larger measurements of all examples, by the longer spire that is more conical and pointed, and by the longer canal. Furthermore, its aperture is nicely white, in places yellow as with the Str. canarium, and the axial lines of which it is covered with are violet brown, which forms very sharp zigzags, and in some places are simply wavy. The part of the body whorl, close to the columella, is a little yellow. Its straight edge is dilated and thick to the perfect state, slim and membranous at a young stage, with brown crosslinks, sometimes colourless; the kind that makes the shell look dark. The periostracum is thin and yellow. The body of the animal is generally greygreenish, stitched with brown. The filaments of the eye stalks are very long. The operculum is long, reddish and regularly toothed on the sides. The eyes are pale yellow, with a black circle exteriorly, and a brown one near the pupil” (Quoy & Gaimard 1834, p. 73, translated AMD).

Distribution. Laevistrombus vanikorensis is commonly collected in Queensland from the Cape York Peninsula down to Dingo Beach (Figure 6). To the east, it ranges from Rabaul, Papua New Guinea along the island chains to the Wallis and Futuna Islands. In the northwest, it may range from Myanmar (Burma) to south Vietnam, Philippines and Indonesia, although these populations are not linked to the southwest Pacific populations. There are three historical institutional records for the Keppel Bay region. However, recent examples of white specimens sold by dealers purporting to come from Keppel Bay (VC, TM) are considered unverified. One further institutional record indicating a more southerly distribution is also considered dubious: New South Wales, Long Bay, Sydney, with the single specimen taxonomically problematic as it resembles specimens more typical of L. turturella from the northwestern Pacific. Records: Australia —Bedford Beach, Cooktown (Abbott 1960); Hayman Island (Abbott 1960); Mossman (Rippingale & McMichael 1961; Cernohorsky 1972); Murray Island, Torres Straits (Melvill & Standen 1899); Port Douglas (Abbott 1960). Solomon Islands— Florida Island (Solem 1958). New Caledonia — Touho Bay (Abbott 1960); Baie de l’Orphelinat (Abbott 1960). Material examined from private collections: Australia Alexandra Reef (SM x 134); Archer Point (SM x 1); Bowen Sand Flats (SM x 1); Cape York Peninsula (SM x 7); Cockle Bay, Magnetic Island (SM x 1); Cooya Beach (SM x 7); Dingo Beach (AMD x 1, SM x 16); Double Island Cairns (SM x 4); Four Mile Beach (AMD x1,SM x 114); Garners Beach (SM x 1); Gloucester Passage (AMD x 1); Kurrimine Beach (SM x 7); Machans Beach (SM x 2); Oak Beach (SM x 3); Pallarenda (AMD x1, SM x 6); Saunders Beach (SM x 1); Shelly Beach, Townsville (SM x 1); Wonga Beach (SM x 11); Yorkeys Knob (SM x 2); Yule Point (SM x 187). Papua New Guinea— Bootless Bay (SM x 1); Porebalda (VC x1); Rabaul (SM x1); Rokui (SM x 2). Solomon Islands —Boli Passage (SM x 1; TM x2; VC x 1); Kolambangara Island (TM x1); Marau Sound (AMD x 1). New Caledonia —No data (AMD x1); Thio (AMD x 2); Ouvéa Island (AMD x 1). Wallis and Futuna —No data (AMD x 1).

Discussion. Laevistrombus vanikorensis is only associated with near-shore habitats, and is not known from the outer reef system. The benthic substrate that this species prefers is highly variable, and it has been observed living in muddy (Dingo Beach), rubbly (Wonga Beach), fine clean (Archer Point) and silty (Alexandra Reef) sand types. This species is highly gregarious, and adults appear to migrate only within a small home range. Within an adult colony, there are consistent, and significant, sexual dimorphism and sex imbalance, with females being both larger and more numerous than males (Maxwell et al. 2017).

Laevistrombus vanikorensis possesses a high degree of consistency in the patterning of dark zigzag lines on a white to cream background. However, the frequency and distribution of these lines can be quite variable. In the eastern parts of the range, pale and white shells are known. Specimens from the western part of the range, particularly Queensland, have a distinctive bluish band below the suture, which is often missing in eastern specimens. A rare golden form is also known from Queensland.

Limitations. The determination of the range of L. vanikorensis from literary sources without illustration is problematic; particularly with the locality records of the three sympatric species encapsulated within those of L. canarium (see Abbott 1960). Therefore, a greater emphasis on actual distribution has been given to collection material over literary records.