Distribution and species composition of freshwater Prosobranchs (Gastropoda) in two locations of Malaysian Borneo

Freshwater gastropods play a vital role in tropical ecosystems, acting as grazers, detritivores, and bioindicators of water quality. Despite their ecological significance, information on their diversity and distribution in Malaysian Borneo remains limited. This study investigated the diversity and distribution of freshwater prosobranch gastropods at two locations in Malaysian Borneo, documenting a total of seven species from three families: Pachychilidae (Melanoides tuberculata, Sulcospira pageli, S. schmidti, S. testudinaria, Brotia costula), Nassariidae (Clea nigricans), and Paludomidae (Paludomus everetti). Pachychilidae was the most diverse and abundant family, comprising five species and 82 individuals. Paludomus everetti had the highest abundance with 24 individuals, while B. costula was the only species found at both locations, indicating broader ecological tolerance. Other species were found at only one location, reflecting specific habitat requirements, water quality preferences, and limited dispersal abilities associated with viviparous reproduction. These findings emphasize the role of biological traits and environmental conditions in shaping gastropod assemblages in tropical freshwater ecosystems. Future studies that integrate detailed abiotic measurements and diversity indices are recommended to enhance understanding of species-specific distribution patterns. The outcomes of this study provide important baseline information that can guide freshwater biodiversity conservation, habitat management, and sustainable resource use in alignment with regional and global ecological priorities.