Gudeodiscus Messageri

''Gudeodiscus messageri'' is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Plectopylidae.

Subspecies

''Gudeodiscus messageri'' include two subspecies:
* ''Gudeodiscus messageri messageri'' (Gude, 1909)
* ''Gudeodiscus messageri raheemi'' Páll-Gergely & Hunyadi, 2015

Distribution

The distribution of ''Gudeodiscus messageri messageri'' is known from Vietnam along the Chinese border (Yunnan Province).

The distribution of ''Gudeodiscus messageri raheemi'' is known from Vietnam from Ninh Bình Province, Thanh Hóa Province, Sơn La Province, Hòa Bình Province and Nghệ An Province and from Luang Prabang Province in north Laos and Vientiane Province in northwest Laos. ''Gudeodiscus messageri raheemi'' in Laos is the westernmost record of the genus ''Gudeodiscus''.

Description

The shell of ''Gudeodiscus messageri'' is small to medium-sized, with slightly elevated spire. The dorsal surface is somewhat domed. The aperture is almost circular. The apertural fold is missing. Callus is rather blunt and only slightly curved. Parietal wall has two lamellae (the anterior lamella may be dissolved into small denticles). Lower parietal plica is free or connected to the anterior lamella. Palatal plicae are oblique, or depressed Z-shaped, usually in contact with each other.

Gudeodiscus messageri messageri

The most important shell characters for identification of ''Gudeodiscus messageri messageri'' include: slightly elevated spire, callus is not angled in the middle, apertural fold is always missing. Other characteristics include: anterior lamella is normal (it is not dissolved into small denticles). Lower parietal plica does not extend beyond the anterior lamella in the anterior direction. The width of the shell is 12.75–18.5 mm.

Views of the shell of ''Gudeodiscus messageri messageri'' by Gerard Pierre Laurent Kalshoven Gude:

Gudeodiscus messageri raheemi

The most important shell characters for identification of ''Gudeodiscus messageri raheemi'' include: body whorl is less shouldered than that of the nominotypical subspecies, but plicae have to be observed for correct identification.

Views of the shell of ''Gudeodiscus messageri raheemi'':

The radula of ''Gudeodiscus messageri raheemi'' has 8 lateral teeth and 16 marginal teeth. The size of the central tooth is as large as or larger than the ectocone of the first lateral. The shape of the first lateral is rhomboid and pointed. Marginal teeth are tricuspid with rather sharp inner cusp and deep incision between the cusps.

Embryos were recorded to be present in the uterus. There were not recorded calcareous granules on the internal surface of penis.

Ecology

It is a ground-dwelling species as all other plectopylid snails in Vietnam. It lives in primary forests and in old secondary broad-leaved forests. It can be found in the humid microenvironments under leaves, logs, limestone rocks and in black soil accumulated inside limestone pockets.

It co-occur with other plectopylids in Vietnam: with ''Gudeodiscus phlyarius'' and with ''Gudeodiscus hemmeni''. It also co-occur with clausiliid '' Garnieria mouhoti'', that is also associated with the moderate humidity of broad-leaved forests.

References

This article incorporates Creative Commons (CC-BY-4.0) text from the referencesPáll-Gergely B., Hunyadi A., Ablett J., Luong Van H., Naggs F. & Asami T. (2015). "Systematics of the family Plectopylidae in Vietnam with additional information on Chinese taxa (Gastropoda, Pulmonata, Stylommatophora)". ''ZooKeys'' 473: 1–118. .Páll-Gergely B., Muratov I. V. & Asami T. (2016). "The family Plectopylidae (Gastropoda, Pulmonata) in Laos with the description of two new genera and a new species". ''ZooKeys'' 592: 1-26. .

{{Taxonbar, from=Q28432413

Gudeodiscus
Gastropods described in 1909