High-altitude molluscs of Ladakh: a first checklist with new records from this cold desert ecosystem

Non-marine molluscs are important components of freshwater and terrestrial ecosystems and serve as valuable indicators of environmental health and habitat quality. However, their diversity in the high-altitude cold desert region of Ladakh remains poorly documented. The present study provides the first comprehensive checklist of non-marine molluscs from Ladakh based on systematic field surveys and taxonomic identification. A total of 32 species belonging to 23 genera and 17 families were recorded. The most species-rich families were Lymnaeidae (9 species), Planorbidae (5 species), and Valloniidae (3 species). Three taxa, Succinea sp., Deroceras laeve, and Odhneripisidium kuiperi are reported for the first time from Ladakh. Gastropods accounted for 90.3% of the recorded species, whereas bivalves represented 9.7%. Freshwater molluscs comprised 66.7% of the total species richness, while terrestrial molluscs contributed 33.3%. Despite the ecological significance of molluscs, no targeted conservation initiatives currently exist for the Trans-Himalayan region of Ladakh, primarily due to limited information on their distribution, population status, and potential threats. This study establishes the first baseline inventory of non-marine molluscan diversity in Ladakh and underscores the need for continued biodiversity assessments, integrative taxonomic investigations, and conservation planning to enhance understanding and protection of the region’s unique malacofauna.