Host specificity of parasitic gastropods of the genus Annulobalcis Habe, 1965 (Mollusca, Gastropoda, Eulimidae) from crinoids in Vietnam, with descriptions of four new species
Author
DGEBUADzE, Polina Y.
Author
FEDOSOv, Alexander E.
Author
Kantor, Yuri I.
A. N. Severtzov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninskiy prospect 33, Moscow 119071 (Russia) p. dgebuadze @ gmail. com
text
Zoosystema
2012
2012-03-31
34
1
139
155
http://dx.doi.org/10.5252/z2012n1a6
journal article
10.5252/z2012n1a6
1638-9387
4547144
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
.
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.
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.