Monday, March 27, 2023

[Mollusca • 2023] Diplommatina bulonensis, D. laemsonensis & D. prakaiphetensis • Three New Species of the Land Snail of the Genus Diplommatina Benson, 1849 (Caenogastropoda: Diplommatinidae) from Satun Province, Thailand


Diplommatina bulonensis, D. laemsonensis D. prakaiphetensis 

 Boonmachai, Bergey & Nantarat, 2023

Abstract
The micro land snail genus Diplommatina (family Diplommatinidae) is widely distributed in Southeast Asia and includes many endemic species. Three new species of Diplommatina are described from Satun Province in southern Thailand. Diplommatina bulonensis sp. nov., D. laemsonensis sp. nov. and D. prakaiphetensis sp. nov. are distinguished from other species in the genus by their shell size and shape, the number of radial ribs on the penultimate whorl, the number of whorls, and features of the peristome. The agreement between phylogenetic tree based on analyses of COI and 16S sequences and comparative morphology support the delineation of these new species which, when compared to related species, belong to well-differentiated clades. The K2P distance between any of the three new species and other Diplommatina species included in the molecular phylogenetic analysis was at least 5.5% in COI and 3.9% in 16S. Two of the three new species (D. prakaiphetensis sp. nov. and D. bulonensis sp. nov.) are apparently endemic to Prakaiphet Hill and Bulon Pai Island, respectively. Additionally, we documented a new regional record for D. naiyanetri in Satun Province. These new species and records contribute to the knowledge of Thailand’s land snail biodiversity and highlight the need of conservation protections for regional karst habitats.

Key Words: endemic, limestone, micro land snail, phylogeny, taxonomy

Localities of micro land snail sampling in Satun Province, Thailand.
A. Bulon Pai Island; B. Talutao Island; C. Khao Yai Island; D. Laem Son Hill; E. Prakaiphet Hill; F. Tharn Pliew Waterfall; G. Phu Pha Phet Cave.
The symbols without letters show previous records for different species of Diplommatina that are known from Thailand (Maassen 2001b; Panha and Burch 2005; Tongkerd et al. 2013; Inkhavilay et al. 2019; Dumrongrojwattana et al. 2020).

Shell internal terminology of new species of the genus Diplommatina from Satun Province
under the stereo microscope and the drawing.
A, B. D. bulonensis sp. nov. (Bulon Pai Island);
C, D. D. laemsonensis sp. nov. (Laem Son Hill);
E, F. D. prakaiphetensis sp. nov. (Prakaiphet Hill).

Shell morphology of Diplommatina from Satun Province.
A. D. bulonensis sp. nov. (Holotype CMUZ 9050001; Bulon Pai Island);
B. D. laemsonensis sp. nov. (Holotype CMUZ 9050019; Laem Son Hill);
C. D. prakaiphetensis sp. nov.  (Holotype CMUZ 9050066; Prakaiphet Hill);
D. D. naiyanetri (CMUZ 905090; Tarutao Island);
E. D. canaliculata (CMUZ 9050158; Tharn Pliew Waterfall).


 Tuangthong Boonmachai, Elizabeth A. Bergey and Nattawadee Nantarat. 2023. First Record and Description of Three New Species in the Land Snail Genus Diplommatina Benson, 1849 (Caenogastropoda, Diplommatinidae) from Satun Province, Thailand. Zoosystematics and Evolution. 99(1): 195-207. DOI: 10.3897/zse.99.99030