Five new species of the land snail genus Landouria Godwin-Austen, 1918 (Gastropoda, Camaenidae) from northeastern Thailand, with note on genitalia and radula morphology of Landouria diplogramma (Möllendorff, 1902)

Abstract

Five new species of the terrestrial snail genus Landouria Godwin-Austen, 1918 (Camaenidae) are described from northeastern Thailand, based on shell features, radular morphology, genital anatomy, and DNA sequence data: Landouria circinata sp. nov., L. tuberculata sp. nov., L. trochomorphoides sp. nov., L. chloritoides sp. nov., and L. elegans sp. nov. These species are phylogenetically well separated from each other by mtDNA phy-logeny and COI sequence divergences of 0.073–0.156. The record of Thaitropis Schileyko, 2004 (currently synonymized with Landouria) in Thailand is re-interpreted as referring to L. diplogramma (Möllendorff, 1902) comb. nov.

New species of the dancing semislug Cryptosemelus Collinge, 1902 (Eupulmonata, Ariophantidae) from Loei Province, northeastern Thailand with a key to genera of mainland Southeast Asian semislugs and a key to species of the genus

“…Since 2007, an intensive survey on land snail diversity in limestone and non-limestone hills in northeastern Thailand has been continuously conducted and published ( Tumpeesuwan 2007 ; Tumpeesuwan and Tumpeesuwan 2010a , 2010b ; Srihata et al 2010 ; Tanmuangpak et al 2012 ; Jumlong et al 2013 Tumpeesuwan et al 2014 ; Tanmuangpak 2016 ; Sasang 2019 ; Nahok 2020 ). In total, 16 species have been described as new to science, comprising 11 species from limestone hills, four species from sandstone hills, and one species from volcanic hills ( Tumpeesuwan and Tumpeesuwan 2014 , 2017 , 2019a , 2019b ; Tanmuangpak et al 2015 , 2017 ; Nahok et al 2020 , 2021a , 2021b ; Deeprom et al 2022 ; Tanmuangpak and Dumrongrojwattana 2022 ; Tongkerd et al 2023 ). Future studies on the malacofauna of the northeastern part of Thailand require more surveys in overlooked and isolated natural areas.…”

Molecular phylogeny of the land snail family Euconulidae in Thailand and its position in the superfamily Trochomorphoidea (Stylommatophora: Limacoidei), with description of a new genus

“…This is due to the key zoogeographical position (a snail fauna comprising Indo-Himalayan, Malaysian and Indo-Chinese taxa), tropical climate with mostly high humidity and the extensive ranges of limestone karsts that are scattered and isolated as small limestone hills and outcrops from the north to the south (Gupta 2005;Clements et al 2006;Naggs et al 2006;Ridd et al 2011). In particular, the limestone karsts of northern and north-eastern Thailand harbour a very rich diversity of land snails and dozens of new species have been newly described, increasing the richness of the endemic terrestrial malacofauna of Thailand (Tanmuangpak et al 2017;Tumpeesuwan and Tumpeesuwan 2017;Nahok et al 2021;Jirapatrasilp et al 2021a;Pholyotha et al 2021aPholyotha et al , 2021b. The dependence of snails on limestone is presumably related to the availability of calcium carbonate in the limestone habitats that is required for shell growth and reproduction (Graveland et al 1994;Barker 2001).…”

Molecular investigation on diversity of the land snail genus Aegista (Gastropoda, Camaenidae) in South Korea

“… Aegista Albers, 1850 is a large genus of the land snail family Camaenidae Pilsbry, 1895 and distributed in south, southeast and east Asian countries (from India and Nepal to Korea and Japan) ( Hirano et al 2015 , Nurinsiyah et al 2019 ). Although some researchers treat Landouria Godwin-Austen, 1918 as a distinct genus ( Köhler et al 2018 , Nahok et al 2021 ), as suggested by Hirano et al (2014) , we treated members of the genus as Aegista in this study because the monophyly of Landouria is still unclear. Fourteen species and subspecies of Aegista are known from South Korea ( Kuroda 1958 ).…”