Dicharax (?) candrakirana n. sp. (Gastropoda: Cyclophoridae) from Sempu Island, Indonesia
Author
Nurinsiyah, Ayu Savitri
Author
Hausdorf, Bernhard
text
Zootaxa
2017
2017-12-13
4363
4
589
591
journal article
31172
10.11646/zootaxa.4363.4.12
5e7426db-618e-4be0-818a-0f1b4e11539b
1175-5326
1114811
90765905-FD57-4412-BE16-01DF1E04E6D5
Dicharax
Kobelt & Möllendorff, 1900
Dicharax
(?)
candrakirana
n. sp.
Diagnosis.
Dicharax
(?)
candrakirana
n. sp.
is characterized by a small, depressed conical shell, with a smooth protoconch and an irregularly striated teleoconch, with spiral striae especially around the umbilicus, and with a short sutural tube about a quarter of a whorl posterior to the aperture from which 5–9 radial microtunnels extend.
Shell (
Fig. 1
).
Depressed conical; with 3 whorls separated by a deep suture. Protoconch low, smooth. Teleoconch irregularly striated, especially at the bottom side around the umbilicus with spiral striae, less distinct spiral striae are present also on the upper side close to the suture. Color whitish; subtranslucent. Last whorl rounded, with an indistinct constriction about a quarter of a whorl posterior to the aperture; posterior to the constriction with a short (
0.25–0.3 mm
long) sutural tube; below the tube with 5–9 radial microtunnels. Aperture almost circular, not crenulated; upper insertion of the peristome descending towards aperture; insertions of the peristome connected by a thick callus; peristome expanded, but not reflexed, strongly thickened inside. Umbilicus wide, eccentric.
Measurements (n = 8): shell diameter D: 2.0–
2.2 mm
, mean 2.1 +
0.05 mm
; shell height H:
1.25–1.3 mm
, mean 1.25 +
0.05 mm
; aperture (outer peristome) diameter da:
0.85–0.9 mm
, mean 0.85 + 0.0 mm; aperture height ha:
0.85–0.9 mm
, mean 0.85 + 0.0 mm; D/H: 1.63–1.71, mean 1.67 + 0.03.
Remarks.
Kobelt (1902)
classified
Dicharax
and
Chamalycaeus
Möllendorff, 1897
as subgenera of
Alycaeus
Gray, 1850
and distinguished
Dicharax
from
Chamalycaeus
by the position of the constriction and the presence of a swelling near the aperture. In contrast,
Páll-Gergely
et al.
(
2017
)
classified these two taxa as genera and distinguished
Chamalycaeus
from
Dicharax
based on the presence of elevated spiral striations on the teleoconch. Whereas
D. candrakirana
n. sp.
would be classified in
Chamalycaeus
according to the diagnosis of
Kobelt (1902)
, its classification is more problematic with regard to the classification of
Páll-Gergely
et al.
(2017)
. There are distinct spiral lines at the bottom side around the umbilicus and less distinct spiral lines on the upper side close to the suture. However, the spiral lines are not elevated ridges as in
Chamalycaeus
.
Páll-Gergely
et al.
(2017)
found spiral striations also in a population of
Dicharax depressus
(Bavay & Dautzenberg, 1912)
of
Vietnam
, which they nevertheless classified in
Dicharax
. We follow a recommendation of B. Páll-Gergely (pers. comm.) and classify the new species also preliminarily in
Dicharax
.
FIGURE 1.
Dicharax
(?)
candrakirana
n. sp.
Indonesia: Malang, Sempu Island, at entrance of Kelabang Cave (holotype MZB 19025). Scale bar = 1 mm.
FIGURE 2.
Type locality of
Dicharax
(?)
candrakirana
n. sp.
: limestone rocks at entrance of Kelabang Cave on Sempu Island, Indonesia.
Dicharax
(?)
candrakirana
n. sp.
differs from
Dicharax longituba
(
Martens, 1864
)
of
Java
and
Sumatra
in the smaller shell with a shorter sutural tube, an only indistinct constriction without swelling, the lack of ribbing and the presence of spiral striae at the bottom side around the umbilicus. It differs from
Chamalycaeus fruhstorferi
(
Möllendorff, 1897
)
of
Java
and
Chamalycaeus kessneri
Vermeulen, 1996
of
Bali
and Nusa Penida in the smaller shell with fewer whorls and the lack of ribbing and elevated spiral striations.
Type
material.
Holotype
:
Indonesia
,
East Java
:
Malang
,
Sempu Island
, limestone rocks in lowland rainforest at entrance of
Kelabang Cave
,
44 m
a.s.l.
,
8°26'58"S
112°41'28"E
(
MZB
19025, leg.
A.S. Nurinsiyah
& H.
Fauzia
9 June 2014
; measurements: D =
2.2 mm
, H =
1.3 mm
)
.
Paratypes
:
Indonesia
,
East Java
:
Malang
,
Sempu Island
, limestone rocks at entrance of
Kelabang Cave
,
44 m
a.s.l.
,
8°26'58"S
112°41'28"E
(
MZB
19026/1;
ZMH 133203
/2); Malang,
Sempu Island
, summit of Kembar Satu Hill,
65 m
a.s.l.
,
8°27'20"S
112°41'28"E
(
MZB
19027/2;
ZMH 133204
/1);
Malang
,
Sempu Island
,
Jembatan Anakan Hill
,
46 m
a.s.l.
,
8°27'05"S
112°41'28"E
(
MZB
19028/1).
Type
locality (
Fig. 2
).
Indonesia
,
East Java
:
Malang
,
Sempu Island
, limestone rocks in lowland rainforest at entrance of
Kelabang Cave
,
44 m
a.s.l.
,
8°26'58"S
112°41'28"E
.
Distribution.
The new species is known only from limestone rocks in lowland rainforest on Sempu Island in
Indonesia
.
Etymology.
The species is named after Candra Kirana, a beautiful princess in the famous Indonesian folk tale ‘Keong Mas’, the ‘Golden Snail’.