Re-description of the type species of the genera Ganesella Blanford, 1863 and Globotrochus Haas, 1935; with description of a new Ganesella species from Thailand (Eupulmonata, Camaenidae)
Author
Sutcharit, Chirasak
Author
Backeljau, Thierry
Author
Panha, Somsak
text
ZooKeys
2019
870
51
76
http://dx.doi.org/10.3897/zookeys.870.36970
journal article
http://dx.doi.org/10.3897/zookeys.870.36970
1313-2970-870-51
BEC530D3DD9A466AAAC705305B20E761
Genus
Globotrochus Haas, 1935
Ganesella (Globotrochus)
Haas, 1935: 47.
Zilch 1960
: 611.
Zilch 1966
: 210.
Globotrochus
:
Schileyko 2003
: 1519.
Schileyko 2011
: 46.
Type species.
Helix onestera
Mabille, 1887, by monotypy.
Description.
Shell trochoid, thin, translucent, 4-6 slightly convex whorls. Last whorl angulated or carinated, slightly descending in front. Colour light yellowish-brown. Embryonic shell smooth. Post apical whorls with irregular, thin, radial ridges and spiral line (smooth below peripheral angle or keel). Aperture ovate, moderately oblique, with slightly expanded and reflexed margins. Umbilicus closed. Shell height ranged from 16 to 17 mm and shell width ranged from 21 to 22 mm.
Genitalia typical of camaenids, but with thin (small size and fully functional) male genital organs (penis and epiphallus).
Radular teeth triangular and tricuspid.
Remarks.
The weak development of male genitalia in
Globotrochus
is unusual among the Indochinese taxa, but is common in papuinid genera, such as
Papustyla
Pilsbry, 1893,
Letitia
Iredale, 1941,
Papunella
Clench & Turner, 1959 and
Wahgia
Clench & Turner, 1959 (
Schileyko 2003
). However,
Papuininae
are geographically confined to New Guinea, Australia and Melanesia (
Schileyko 2003
), and have never been recorded in Indochina. Therefore, it seems as if 'weak male genital
parts'
is an autapomorphy of
Globotrochus
.
Globotrochus
differs from all other camaenid genera in Indochina (i.e.,
Chloritis
,
Satsuma
,
Ganesella
and
Neocepolis
) by its weakly developed male genital organs. In contrast, the genera
Chloritis
,
Ganesella
and
Neocepolis
have typical camaenid genitalia, with well-developed male genital organs, including a relatively short to long penis, an epiphallus and penial verge, and a short to long flagellum. Furthermore,
Ganesella
has no penial appendix.
Satsuma
has a fully-developed male genital organ, with a short to long penial appendage, but without a penial verge (
Solem 1993
,
Schileyko 2003
,
2004
,
Sutcharit et al. 2007
,
Sutcharit and Panha 2010
).
Currently, only two nominal species are assigned to
Globotrochus
. Based on the literature, museum specimens and recent field surveys, it seems as if
Globotrochus
is restricted to the north of Vietnam (
Vermeulen and Maassen 2003
,
Schileyko 2003
,
2011
). However, an ambiguous locality record from Elephant Mountain, Laos (sensu
Schileyko 2011
: 46) needs verification.