Annulobalcis vinarius, DGEBUADzE & FEDOSOv & Kantor, 2012

DGEBUADzE, Polina Y., FEDOSOv, Alexander E. & Kantor, Yuri I., 2012, Host specificity of parasitic gastropods of the genus Annulobalcis Habe, 1965 (Mollusca, Gastropoda, Eulimidae) from crinoids in Vietnam, with descriptions of four new species, Zoosystema 34 (1), pp. 139-155 : 148-150

Annulobalcis vinarius n. sp.

( Figs 4 ; 6 C-E)

Annulobalcis sp. 2 – Dgebuadze & Kantor 2010: figs 2b, g; 4b.

TYPE MATERIAL. — Vietnam. South China Sea, Nha Trang Bay, Mun Island (Rock Rom), 12°10’12.51”N, 109°18’46.06”E, 5-7 m, holotype ( MNHN 24194).

Same data as holotype, 4 paratypes ( ZIN 61122, 61123, MNHN 24195).

OTHER MATERIAL EXAMINED. — 1440 specimens from several species of crinoids, 5 specimens sequenced ( JF717850 - JF717854 ), stored in the Laboratory of Marine Invertebrates of A. N. Severtzov Institute of Ecology and Evolution.

DISTRIBUTION. — South China Sea, Nha Trang Bay.

ETYMOLOGY. — From the Latin “vinarius”, wine merchant, reflecting wine-red colours of soft parts of live specimens.

DESCRIPTION (HOLOTYPE)

Shell thin, transparent, narrow, glossy, elongatedconical, with well-developed irregularly situated growth lines and scars. Shell of 8.5 whorls.

Larval shell of about two smooth broad whorls, separated by shallow impressed suture. Boundary between protoconch and teleoconch marked by changing of suture type and appearance of false suture seen by transparency (not visible on SEM photograph; Fig. 4I ).

Teleoconch whorls slightly convex.Expansion rate nearly constant. Spiral sculpture not pronounced. Suture clearly adpressed. Last whorl high, 0.59 of shell height. Shell axis not curved.

Aperture broadly ovate, with visible angle between columellar and parietal margins, 0.38 of shell height. Parietal margin evenly rounded, slightly convex, without callus. Columellar margin short, slightly convex, nearly flat, about ⅔ of aperture height. Outer lip in ventral view evenly rounded, in lateral with distinct sinus below suture, evenly protruded and curved in middle part.

Soft parts clearly visible through shell.

Measurements

See Table 5.

Host

Holotype and paratypes were found on calyx (lower and upper side), on arms, on cirri of crinoids Himerometra robustipinna Carpenter, 1881 (Himerometridae) . Other specimens were found on a wide range of hosts: Comatella nigra Carpenter, 1888 (Comasteridae) ; Stephanometra indica (Smith, 1876) ; Dichrometra flagellata (Müller, 1841) (Mariamtridae) ; Stephanometra tenuipinna (Hartlaub, 1890) ; Amphimetra ensifera (A. H. Clark, 1908) (Himerometridae) . On a specimen of Comatella nigra it was co-occuring with A. maculatus n. sp.

Morphology and colouration

In live specimens body dark red with small white spots arranged in axial bands regularly situated on whorls of visceral mass. On last whorl, spots irregularly scattered. Foot large, narrow, dark red with white spots and white edges.Tentacles red with white tips.Eyes well developed,black, situated at base of tentacles. Proboscis present. Mantle transparent with well-marked white edge. Pseudopallium absent. Operculum present, oval, spiral, nucleus close to columellar margin ( Fig. 4N ).

Intraspecific variability

Paratypes are very similar to holotype in shell shape and morphology with slight variation in slenderness and relative aperture height. The smallest paratype has a broader shell, but the tendency is not well pronounced. The largest paratype has more or less regularly distributed white spots on the last body whorl.

REMARKS

The present species resembles Annulobalcis yamamotoi from Japan and Annulobalcis aurisflamma from Brazil in transparent shell and brightly coloured spotted soft parts, but differs in the absence of spiral sculpture, as well as in the shell shape, shell width and height ratio. For the differences with A. maculatus n. sp. see the description of the latter. One of the specimens deposited four egg-capsules during observations ( Fig. 6E ). Egg capsules are attached to the host, bean-shaped, semi-transparent up to 5.5 mm in length. Eggs are very numerous and small.

Figures

FIG. 4. — Annulobalcis vinarius n. sp.: A, B, holotype (MNHN 24194); C, paratype 1 (ZIN 61122); D, E, paratype 2 (ZIN 61123); F, G, paratype 3 (MNHN 24195); H, paratype 4 (MNHN 24195); I, specimen 3 (Table 5) collected from the same host as the sequenced ones, apex, SEM; J, sequenced specimen 2 (Table 5) (GenBank no. JF717854); K, L, specimen, collected from the same host as the sequenced ones; M, specimen 3, SEM of the shell; N, same, operculum, SEM. Scale bars: A-H, J-M, 1 mm; I, 100 μm; N, 500 μm.

FIG. 6. — A, live specimen of Annulobalcis albus n. sp.; B, Annulobalcis albus n. sp. specimens on their host Oxycomanthus benetti (Müller, 1841); C, Annulobalcis vinarius n. sp. on arm of crinoid Himerometra robustipinna Carpenter, 1881; D, live specimen of Annulobalcis vinarius n. sp.; E, eggs capsules of Annulobalcis vinarius n. sp. on crinoid Himerometra robustipinna; F, live specimen of Annulobalcis wareni n. sp. Scale bars: A, C-F, 1 mm; B, 10 mm.