Researchers have identified four new species of tiny land snails in the limestone hills of Laos, shedding light on the rich biodiversity of the region. The findings were published in the journal ZooKeys, highlighting eight species of operculate micro land snails from the subfamily Alycaeinae discovered during biodiversity surveys in Vientiane and Houaphanh provinces. The study was conducted by a team from Chulalongkorn University in Thailand and the National University of Laos.
The new species are named Dioryx feuangensis, Dicharax feuangensis, Dicharax pallgergelyi, and Pincerna panhai. Additionally, researchers identified Dioryx dongiensis for the first time in Laos, extending its known range by over 400 kilometers from its original location in Vietnam’s Cuc Phuong National Park. The survey also included three other identified species: Metalycaeus heudei, Dicharax cristatus, and Pincerna vanbuensis.
Alycaeine snails, known for their unique biological adaptations, possess a hard operculum that serves as a trapdoor to seal the shell’s opening. They also feature a distinctive breathing apparatus consisting of a sutural tube and microscopic tunnels that enable them to breathe air even when sealed inside their shells. More than 300 species of these snails are documented across Southeast Asia.
The researchers meticulously collected empty shells from various locations, including limestone outcrops and caves, in 2022 and 2024. Using advanced microscopy, they analyzed the shells for size, shape, and surface markings, allowing them to differentiate the closely related species. Each new species showed distinct characteristics, such as the solid, yellowish shell of Dioryx feuangensis and the remarkably small size of Dicharax pallgergelyi.
The naming of the species reflects notable individuals and locations relevant to the research. For instance, Dicharax pallgergelyi honors Hungarian malacologist Dr. Barna Páll-Gergely, while Pincerna panhai is named in recognition of Professor Somsak Panha from Chulalongkorn University.
Researchers observed co-occurring species at specific limestone hills, prompting questions about their ecological interactions. They suggested possible explanations for this phenomenon, including resource availability or competition dynamics within the leaf litter and rock crevices.
Limestone karsts in Laos span approximately 30,000 square kilometers, serving as evolutionary islands that contribute to the region’s endemic snail populations. The recent study adds to the growing list of malacological discoveries in Laos, which now records over 240 land snail species, including more than 120 described as new in recent decades.
Despite the biodiversity richness, the areas explored in this study do not fall within Laos’ designated Key Biodiversity Areas, raising concerns about conservation efforts. The authors emphasized the urgency for greater protection of these vulnerable limestone ecosystems as human activities like quarrying, agriculture, and logging threaten their integrity.
Moving forward, the research indicates that enhanced methods for soil and shell recovery could uncover even more undiscovered species. The findings serve as a reminder of the ecological treasures that remain hidden beneath the forest floor in Laos.
