Mollusk fauna and regional distribution of the Kelkit Basin, Türkiye

This study was conducted between October 2023 and October 2024 at a total of 85 stations covering the provinces of Gümüşhane, Giresun, Erzincan, Ordu, Tokat, and Sivas, with the aim of determining the freshwater mollusk fauna of the Kelkit Basin. The taxonomic identifications and habitat characteristics of the species recorded during the research were determined. From the study area, seven families belonging to the class Gastropoda were identified, including the species Oxyloma elegans, Peregriana labiata, Gyraulus piscinarum, Physella acuta, Potamopyrgus antipodarum, Valvata macrostoma, and Theodoxus fluviatilis. From the class Bivalvia, Dreissena polymorpha gallandi and Dreissena caputlacus were identified. In the Kelkit Basin, the alien invasive mollusks D. caputlacus, D. p. gallandi, P. acuta, and P. antipodarum were recorded from Kılıçkaya Reservoir, Çamlıgöze Reservoir, and Tepekışa Reservoir, but not from Sadak Reservoir and Gölova Reservoir. Potamopyrgus antipodarum, which has previously been reported to spread across many regions of Türkiye, was recorded from this basin for the first time. The potential impacts of this occurrence on the Kelkit Basin were also discussed.