Monday, November 21, 2022

[Mollusca • 2022] Quantula doma • A New Species of the Genus Quantula Baker, 1941 (Eupulmonata: Dyakiidae) from north-eastern Thailand


A, Quantula weinkauffiana (Crosse & Fischer, 1863)
 B–C,  Quantula doma 
Deeprom, Tumpeesuwan & Tumpeesuwan, 2022


Abstract
The land snail genus Quantula Baker, 1941 from the southern part of north-eastern Thailand was studied. The results of studies on shell morphology, reproductive anatomy, and molecular phylogeny reveal the distinctions between two species—Quantula weinkauffiana (Crosse & Fischer, 1863) and Quantula doma, new species. According to shell morphology and genitalia, Q. weinkauffiana from Khao Phanom Sawai, Surin Province, has a depressed shell with a whorl descending in front, short gametolytic sac that is connected to the middle part of the amatorial organ, and amatorial organ duct shorter than amatorial organ, whereas Q. doma, new species from Khao Sala in Surin, Pha Nam Yoi in Roi Et, and Phu Jor Kor in Mukdahan Provinces has a dome-shaped to depressed conic shell, last whorl not descending in front, and amatorial organ duct longer than amatorial organ. Both species are also phylogenetically separated from each other by mitochondrial DNA phylogeny and COI sequence divergences. 

Key words. inner wall of genitalia, phylogenetics, Quantula striata, Quantula weinkauffiana, Quantula godwinausteni

Living snails of Quantula spp. in the southern part of north-eastern Thailand. A, Q. weinkauffiana (NHMSU-00035) from Phanom Sawai, Surin; B–C,  Q. doma, new species: B, NHMSU-00049 from Khao Sala, Surin; C, NHMSU-00051 from Phu Jor Kor, Mukdahan.

Shell morphology of Quantula spp. in the southern part of north-eastern Thailand.
A, Q. weinkauffiana, specimen NHMSU-00035 from Phanom Sawai, Surin; B–C, Q. doma, new species: B, holotype NHMSU-00048 from Khao Sala, Surin; C, NHMSU-00050 from Phu Jor Kor, Mukdahan.


Quantula doma, new species

Diagnosis. Last whorl angular with peripheral keel, not descending in front. Amatorial organ duct longer than amatorial organ. 

Etymology. The specific epithet is derived from the Latin word ‘domus’ meaning roof, referring to the fact that its shell shape is similar to a hemispherical roof.


Kanchanog Deeprom, Chanidaporn Tumpeesuwan and Sakboworn Tumpeesuwan. 2022. A New Species of the Genus Quantula Baker, 1941 (Eupulmonata: Dyakiidae) from the southern part of north-eastern Thailand. RAFFLES BULLETIN OF ZOOLOGY. 70519–533.