On Two New Species Of Amphidromus (Gastropoda: Camaenidae) From The Lesser Sunda Islands, Indonesia
Author
Chan, S. Y.
Author
Tan, S. K.
text
Raffles Bulletin of Zoology
2010
2010-08-31
58
2
245
249
journal article
10.5281/zenodo.4508354
2345-7600
4508354
Amphidromus
(
Syndromus
)
abbasi
,
new species
(
Figs. 1
A–C)
Material examined. –
Holotype
–
1 ex.
(
MZB
.Gst.14.232), arboreal on low lying bushes and trees along a stream in damp forest just above sea level, about
1.2 km
from the coast, Langgaliru (
9°45'44"S
119°38'33"E
), Southwest Sumba,
Indonesia
, coll.
John Abbas
,
Sep.2007
.
Paratypes
.–
10 ex.
(
MZB
.Gst.14.233)
;
5 ex.
(
ZRC
.MOL.2832–2836)
,
1 ex.
(
ZRC
.MOL.2960)
;
8 ex.
(
CSY409.003
amph048.00/01–08)
;
2 ex.
(
MNHN
)
;
3 ex.
(
BMNH20080623
) – same data as holotype
.
Description. –
Shell thin, sinistral, smooth with somewhat silky lustre; shell height up to
41.3 mm
, width to
16 mm
, aperture height to
21.2 mm
in examined specimens; sinistral and slender ovately conical, covered with a thin periderm; whorls (6.5–7) rather flat, giving the shell a generally straight sided profile; outer lip thin and slightly expanded outwardly but not reflected; columella white, thin, slightly curved, without folds; umbilicus perforated or nearly closed; aperture large, about half of shell height, oblique, peristome basally rounded (“tear-drop” shaped); tip of apex faintly pinkishbrown, some individuals with a brown-black spot; parietal wall thin and transparent; ground colour light yellow or light to dark brown, decorated with variegated radial streaks or flames in the antepenultimate and penultimate whorls and an alternately blotched (somewhat checkered) subsutural spiral band; colour in aperture light yellow to brown.
Distribution. –
Known thus far only from the
type
locality, probably endemic.
Etymology. –
This species is named after Mr. John Abbas who collected, and kindly donated the specimens for our study.
Remarks. –
No distinct dark axial bands marking interruptions in shell development (resting stage or varix) were observed in all examined specimens of
Amphidromus
(
Syndromus
)
abbasi
,
new species
. The alternately blotched subsutural band appears most prominently on the last whorl just above the periphery. The radial bands and patterns are consistent in most specimens examined, but are faintly marked or relatively monotonous in some. According to Laidlaw & Solem (1961), only
Amphidromus
(
Syndromus
)
latestrigatus
Schepman, 1892
, and
Amphidromus
(
Syndromus
)
floresianus
Fulton, 1897
are known from Sumba Island. However, in terms of external morphology,
Amphidromus
(
Syndromus
)
contrarius
(
Müller, 1774
)
(
Fig. 1
, D), and
Amphidromus
(
Syndromus
)
filozonatus
von
Martens, 1867
(
Fig. 1E
) resemble
Amphidromus
(
Syndromus
)
abbasi
,
new species
, more. Some individuals of
Amphidromus
(
Syndromus
)
abbasi
,
new species
, with a light yellow ground colour may resemble similarly coloured
Amphidromus
(
Syndromus
)
contrarius
(
Müller, 1774
)
, while light brown forms are reminiscent of
Amphidromus
(
Syndromus
)
filozonatus
von
Martens, 1867
. Despite the suggested similarities with these congeners, the profile and peculiar teardrop-shaped aperture of
Amphidromus
(
Syndromus
)
abbasi
,
new species
, easily distinguishes it from other known
Amphidromus
(
Syndromus
)
species.