Systematic review of the dextral Hemiplecta Albers, 1850 (Eupulmonata, Ariophantidae) from Thailand with description of a new species and list of all the Indochinese species

Abstract

The genus Hemiplecta is a group of large-sized land snails which have long been used as a food resource by Indochinese people. There are five dextral and four sinistral species currently recognized from Thailand. The dextral group is comprised of two previously recorded species (H. humphreysiana and H. distincta), two newly recorded species (H. funerea and H. esculenta), and one new species (H. nemorosasp. nov.) from northern Thailand is being proposed. We reassessed the diagnostic characters of the genitalia, mantle edge, and radula. Specimens were classified into the genus Hemiplecta on the basis of the penial verge and shell lobe, and on the characters of a bulbous gametolytic sac without a gametolytic duct. A complete species list, together with photographs of the name-bearing types or authenticated specimens and the taxonomic status of Hemiplecta s.l. that are known from Indochina including Peninsular Malaysia and Myanmar, is provided for the first time. In total, this species list contains 39 available nominal species names described from this area. Type or authentic specimens can be located for 37 nominal species names, of which 25 are illustrated herein and the other 12 were recently illustrated. However, two available species-level names could not be traced to any type specimens. In addition, lectotypes of H. funerea and H. pluto are designated herein to stabilize the names.

Annotated checklist of the operculated land snails from Thailand (Mollusca, Gastropoda, Caenogastropoda): the family Pupinidae, with descriptions of several new species and subspecies, and notes on classification of Pupina Vignard, 1829 and Pupinella Gray, 1850 from mainland Southeast Asia

“…A number of operculated land snails from the families Alycaeidae , Cyclophoridae and Diplommatinidae were described ( Panha and Burch 1998 , 2005 ; Panha and Patamakanthin 2001 ; Nantarat et al 2014 , 2019 ; Sutcharit et al 2014 ; Jirapatrasilp et al 2021 ). However, most malacological studies focused on pulmonate land snails, e.g., the families Ariophantidae ( Pholyotha et al 2020 ; Sutcharit and Panha 2021 ), Camaenidae ( Sutcharit and Panha 2006 ), Gastrocoptidae ( Panha and Burch 2005 ), and Streptaxidae ( Siriboon et al 2014a , b ). The 20-year work of SP and his colleagues has culminated in a recent inventory and book on Thai land snails ( BEDO 2017 ; Sutcharit et al 2018 ).…”

Uncovering local endemism from southeastern Myanmar: description of the new karst-associated terrestrial snail genus Burmochlamys (Eupulmonata, Helicarionidae)

“…Previous studies of the anatomy of the Southeast Asian helicarionids and ariophantids noted differences in the mantle morphology (especially the shell lobe), described as a slender or slightly extended shell lobe (i.e., Macrochlamys , Microcystina , and Sitala ), or as a broad and enlarged shell lobe (i.e., Aenigmatoconcha , Chalepotaxis , and Sophina ). So, the mantle morphology can be used as an informative character to distinguish members of these two families even though reduction of the mantle extension within the same genus has been documented ( Blanford and Godwin-Austen 1908 ; Pholyotha et al 2020c ; Sutcharit and Panha 2021 ).…”

Further notes on the taxonomy of the land snail family Clausiliidae Gray, 1855 (Stylommatophora, Helicina) from Myanmar with description of two new species

“…Myanmar is actively promoting knowledge of its malacofauna, especially the material obtained under the framework of a joint project between the Forest Department of Myanmar, the Fauna and Flora International ( FFI ), and the Animal Systematics Research Unit ( ASRU ) of Chulalongkorn University, Thailand. This effort has already provided information regarding the distribution, habitat, and essential morphological characters (e.g., genitalia and radula) of the Myanmarese malacofauna, including the description of several new ariophantids and helicarionids taxa ( Pholyotha et al 2020 , 2022 ; Sutcharit et al 2020a ; Sutcharit and Panha 2021 ) and Streptaxidae ( Sutcharit et al 2020b ; Man et al 2022 ). In this context, the present study provides an up-to-date species list of the door snails from Myanmar, with taxonomic notes, and with a re-description of the shell, genitalia, and radula morphology of several species.…”