Integrative taxonomic revision of the land snail genus Sarika Godwin-Austen, 1907 in Thailand, with descriptions of nine new species (Eupulmonata, Ariophantidae)

Abstract

Members of the land snail genus SarikaGodwin-Austen 1907 are superficially similar and difficult to differentiate by their shell morphology so that their species limits are still unclear. In order to resolve the taxonomy of this group, a phylogenetic reconstruction of Sarika is presented, based on morphological and anatomical characters, as well as on partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene. In total, 23 species of Sarika are recognised in Thailand, and nine species are new to science, namely S. caligina Pholyotha & Panha, sp. nov., S. gratesi Pholyotha & Panha, sp. nov., S. inferospira Pholyotha & Panha, sp. nov., S. lactospira Pholyotha & Panha, sp. nov., S. megalogyne Pholyotha & Panha, sp. nov., S. melanospira Pholyotha & Panha, sp. nov., S. pellosa Pholyotha & Panha, sp. nov., S. solemi Pholyotha & Panha, sp. nov., and S. subheptagyra Pholyotha & Panha, sp. nov. Results from genital examination and COI analyses confirm the monophyly of Sarika and its species. The intra- and inter-specific genetic distances of Sarika were 0–3.7% and 4.6–12.0%, respectively. Colour images of the living adults, shell, and genitalia along with SEM images of the spermatophore and radula are given. In addition, an identification key and a geographical distribution map of Sarika species are provided.

Rediscovering the dancing semislug genus Cryptosemelus Collinge, 1902 (Eupulmonata, Ariophantidae) from Thailand with description of two new species

“…In the past decade, knowledge of the species diversity of Thailand’s ariophantid snails has dramatically improved, and many genera/species have been described and their systematics have been revised (i.e., Pholyotha et al 2020 , 2021 ). For the poorly known genus Cryptosemelus Collinge, 1902 such a systematic revision had been pending so far as there had been no additional records on this taxon since its first description.…”

Systematic revision of the limestone karst-restricted land snail genus Aenigmatoconcha (Eupulmonata: Helicarionidae), with description of a new species

“…Other helicarionoids with a whitish shell include Macrochlamys psyche Vermeulen et al, 2019, Sarika lactoconcha Pholyotha & Panha, 2020, and Sarika consepta (Benson, 1860. However, the relatively medium to large-sized shells (shell width larger than 15 mm), narrowly perforate umbilicus, genital structure, and radula with triangular teeth of these three species clearly differentiate them from all Aenigmatoconcha species (Vermeulen et al 2019;Pholyotha et al 2020aPholyotha et al , 2020b. The greatest similarity in shell characters occurred in Sophina and Chalepotaxis, but their genitalia are obviously different.…”

“…The country boasts many unique limestone formations (Naggs et al 2006;Ridd et al 2011;Latinne et al 2013). Thus, Thailand houses many endemic cave-dwelling animals, such as various groups of vertebrates (e.g., Latinne et al 2013;Pauwels et al 2014;Sumontha et al 2017) and invertebrates (e.g., Sedgwick & Schwendinger 1990;Srisonchai et al 2018;Likhitrakarn et al 2020), especially several families of land snails (e.g., Tongkerd et al 2004;Siriboon et al 2014;Dumrongrojwattana & Tanmuangpak 2020;Pholyotha et al 2020bPholyotha et al , 2021Sutcharit et al 2020b). Although the recent studies of karst-associated land snail species in Southeast Asia have flourished, the number of new species discovered has increased every year, supporting that the Thai fauna on limestone karsts, especially land snails, still remains mostly unexplored.…”

“…Generally, helicarionoid snails tend to have a diverse shell form but conserved reproductive organs and mantle lobes. These conserved characters appear to be systematically informative following integrative taxonomic approaches, such as in the Southeast Asian ariophantids (Pholyotha et al 2020b(Pholyotha et al , 2021Sutcharit et al 2020b) and helicarionids (Páll-Gergely et al 2016;Sutcharit et al 2020a), and in the Australian helicarionids (Hyman & Ponder 2010;Hyman & Köhler 2018.…”

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

“…Descriptive terms are oriented with reference to the genital orifice. Abbreviations follow Godwin-Austen (1900, 1919, Schileyko (2002), Pholyotha et al (2020) and Sutcharit et al (2021): ag, albumin gland; aldl, anterior left dorsal lobe; an, anus; at, atrium; da, dart apparatus; dp, dart papilla; e, epiphallus; ec, epiphallic caecum; fl, flagellum; fo, free oviduct; gs, gametolytic sac; h; heart; hd, hermaphroditic duct; hg, hermaphroditic gland; k, kidney; lsl, left shell lobe; ov, oviduct; p, penis; pg, prostate gland; pldl; posterior left dorsal lobe; pr, penial retractor muscle; ps, penial sculpture; psh, penial sheath; puv, pulmonary vein; pv, penial verge; r, rectum; rdl, right dorsal lobe; rsl, right shell lobe; ur, ureter; v, vagina; vd, vas deferens.…”