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 maculatus
n. sp.
(
Fig. 5
)
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 24196
)
.
Same data as holotype,
3 paratypes
sequenced (
ZIN
61124,
JF717847
;
ZIN
61125,
JF717848
;
MNHN 24197
,
JF717849
)
.
OTHER
MATERIAL EXAMINED. —
27 specimens
from crinoids
Comatella nigra
(Comasteridae)
, 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 “maculatus”, spotty, shows the colouration of soft parts in live specimens, red with big light spots.
DESCRIPTION (
HOLOTYPE
)
Shell thin, transparent, narrow, glossy, elongatedconical, with well-developed irregularly situated growth lines and scars. Shell of> 9 whorls.
Larval shell smooth consists of about> 4 whorls. Boundary between protoconch and teleoconch marked by thin sigmoid scar. Protoconch slightly curved, its whorls less convex and have lower expansion rate than whorls of teleoconch.
Teleoconch of five whorls. Suture shallow, false suture seen by transparency, narrow. Body whorl high, 0.56 of shell height. Aperture ovate with angulated junction of columellar and parietal margins, 0.36 of shell height. Parietal margin rounded, slightly convex, without callus. Columellar margin short, bulging, more than half of aperture height, slightly deflected out. Outer lip strongly convex in ventral view in middle part, nearly flat in upper part; basal part with rounded angle; in lateral view, sigmoid shape, with marked anal sinus near the suture.
Soft parts clearly visible through shell.
Measurements
See
Table 6
.
Host
Molluscs were found on lower side of calyx and on cirri of crinoids
Comatella nigra
.
FIG. 5. —
Annulobalcis maculatus
n. sp.
:
A
,
B
, holotype (MNHN 24196);
C
,
D
, paratype 1 (ZIN 61124);
E
, paratype 2 (ZIN 61125);
F
, paratype 3 (MNHN 24197);
G-I
, specimen from the same host as the types;
G
,
H
, shell SEM;
I
, apex, SEM. Scale bars: A-H, 1 mm; I, 200 μm.
Morphology and colouration
In live specimens body dark red with large yellowish spots irregularly situated on the visceral mass
whorls. Eyes well developed, black, situated at base of tentacles. Proboscis present. Operculum present, similar in morphology to other species.
TABLE 6. — Measurements (in mm) of holotype and paratypes of
Annulobalcis maculatus
n. sp.
Specimen
|
SH
|
SW
|
SW/SH
|
AH
|
AH/SH
|
AW
|
LWH
|
LWH/SH
|
Holotype (MNHN 24196) |
6.4 |
2.5 |
0.39 |
2.4 |
0.36 |
1.4 |
3.7 |
0.56 |
Paratype 1(ZIN 61124) |
5.5 |
2.5 |
0.45 |
2.2 |
0.4 |
1.3 |
3.5 |
0.64 |
Paratype 2 (ZIN 61125) |
5.6 |
2.0 |
0.36 |
2.1 |
0.37 |
1.2 |
3.4 |
0.61 |
Paratype 3 (MNHN 24197) |
5.7 |
2.5 |
0.44 |
1.6 |
0.4 |
1.6 |
3.5 |
0.61 |
Intraspecific variability
Paratypes
are very similar to
holotype
in shell shape and morphology.
The shell growth parameters change with size: there is a weak tendency of decreasing of SW/SH ratio with increasing of shell height. There is also a tendency of decreasing of LWH/SH ratio with increasing of the shell height.
REMARKS
The present species resembles
Annulobalcis vinarius
n. sp.
in shell form, absence of spiral sculpture, host preference and distribution. However it differs by a lower number of whorls, more convex whorls, colouration, form and
type
of spots distribution on soft parts. Besides both species are clearly separated by mithocondrial Cox1 sequence.