Revision of the carnivorous snail genus Indoartemon Forcart, 1946 and a new genus Carinartemis from Thailand (Pulmonata: Streptaxidae)
Author
Siriboon, Thanit
Author
Sutcharit, Chirasak
Author
Naggs, Fred
Author
Rowson, Ben
Author
Panha, Somsak
text
Raffles Bulletin of Zoology
2014
2014-04-04
62
161
174
journal article
10.5281/zenodo.4504075
2345-7600
4504075
2300F64E-BD30-4E06-A24F-A226185A4BD3
Carinartemis
Siriboon & Panha
,
new genus
Type
species.
Carinartemis vesperus
Siriboon & Panha
,
new species
.
Diagnosis.
This new genus is noticeably distinct from
Discartemon
and
Perrottetia
by having a strong peripheral keel around nearly the entire penultimate whorl, in having the last whorl less inflated but strongly deviated from the vertical axis, and in having or lacking very thin parietal lamella. Whereas,
Discartemon
possesses a regularly coiled shell, the last whorl does not deviate from the columellar axis, and the apertural dentition varies, with at least a parietal lamella present.
Perrottetia
also has a smaller shell, has longitudinal furrows on outer wall of the last whorl, and always has two parietal and the other lamellae present.
In comparison,
Oophana
and
Indoartemon
have a more inflated last whorl, while the penultimate whorl is rounded to angular.
Oophana
has parietal, palatal, basal, and columellar lamellae, and
Indoartemon
has only parietal and palatal lamellae.
Fig. 4. Genitalia of
Indoartemon medius
,
new species
, paratype CUMZ 5017: A, reproductive system; B, attachment of vas deferens into distal end of the penial sheath; C, details of albumin gland and talon.
The new genus,
Carinartemis
, is superficially similar to
Haploptychius
and
Stemmatopsis
with the last whorl less inflated and much deviated from the vertical axis, and in having or lacking a lamella. However,
Haploptychius
differs from this new genus by having an angular to round peripheral keel around less than half of the penultimate whorl, and with a strong parietal lamella always present. The monotypic
Stemmatopsis
Mabille, 1887
is smaller, has a lower spire, a smooth shell surface, a rounded periphery of penultimate whorl, closed umbilicus, an aperture with an irregularly constricted shape, and a sinuous peristome (
Fig. 6A
;
Mabille, 1887
).
Description.
Shell suboblique-heliciform, white, and translucent; whorls 7, spire low conical with distinct suture. Shell surface with transverse ridges. Embryonic shell with smooth surface; following whorls regularly expanding and penultimate whorl with very sharp and wide peripheral keel. Last whorl round and axially deflected. Umbilicus open and deep. Aperture subcircular, peristome expanded. Apertural dentition with or without parietal lamella and sometimes small other lamellae present.
Genitalia with short atrium; penis long; penial sheath thin to thick. Internal wall of introverted penis with brown penial hooks. Vagina short, free oviduct short to long. Seminal vesicle about as long as the length from the talon to the branching point of the seminal vesicle. Internal wall of vagina with oblique to arched parallel vaginal folds; vaginal hooks may be present.
Live specimens exhibit pale yellowish reticulated skin with brownish spots, and yellowish tentacular retractor muscles are visible through the semi-transparent body (
Fig. 2B, C
).
Etymology.
The generic name
Carinartemis
is derived from the Latin “
carina
” meaning “keel”, and Greek “
artemis
” meaning “goddess of the chase”. It refers to this carnivorous snail that has a prominent peripheral keel on penultimate whorl.
Fig. 5. Internal sculpture of genitalia of
Indoartemon medius
,
new species
, paratype CUMZ 5017: A, details of atrial pore on the atrium surface; B, low magnification shows arrangement of penial hooks; C, high magnification of penial hooks in proximal area; D, top view of penial hook, hooks shrunken in tubed penial papillae; E, low magnification of penial hook in distal area; F, lateral view of penial hook in distal area; G, high magnification of penial hooks in distal area; H, arrangement of vaginal folds; I, radula morphology.
Remarks.
The new genus currently comprises two new species. They are uncommon and seemed to be restricted to the limestone outcrops in western
Thailand
.