Isolation and endemism in the subterranean aquatic snails of the genus Belgrandiella A. J. Wagner, 1928 (Caenogastropoda: Truncatelloidea: Hydrobiidae)

Abstract The Western Balkans hosts the richest subterranean aquatic gastropod fauna in world. main factors shaping intraspecies diversity are thought to be isolation and endemism. In genus Belgrandiella , minute snails inhabiting waters springs Central Europe Balkans, molecular studies have shown much fewer valid species than previously anticipated. present study applies mitochondrial cytochrome c oxidase subunit I, histone 3, RAPD analysis, check inter- genetic 36 populations from caves, interstitial aquifers. level of gene flow is assessed if these form a widespread genetically uniform metapopulation or rather follow highly endemic pattern. studied been assigned six species. most widely distributed B. kusceri 21 populations, 60 sequenced specimens represent 16 haplotypes. While same haplotypes distant between other low. Nei distances for show no geographic interspecies differences COI evidently confirm time speciation Pleistocene, before karstification, which rejects within isolated caves. pattern observed seems more similar one described Montenegrospeum Kerkia .