A hotspot of groundwater amphipod diversity on a crossroad of evolutionary radiations

Aim Groundwater harbours an exceptional fauna and provides invaluable ecosystem services, yet is among the least explored consequently protected ecosystems. Successful protection of its biodiversity depends on complete species inventories, knowledge spatial distribution, quantification patterns, as well disentanglement processes that shaped patterns. We studied hyper-speciose amphipod genus Niphargus a model system within global subterranean hotspot. linked patterns with possible underlying discuss needs to include information different origins into conservation approaches. Location Europe, Western Balkans. Methods analysed using two metrics, richness phylogenetic diversity, grid-based approach. To account for high cryptic we replaced nominal taxonomic units identified in unilocus delimitations (MOTUs). built time-calibrated multilocus phylogeny 512 MOTUs from outside study area, calculated Faith's standardized effect sizes residual diversity regressed onto richness. Results Within recognized 245 MOTUs, belonging clades. Species highest north-western hotspot, although some species-rich cells were detected also south-east. High coincides north-west, while south-east it lower than expected. Main conclusions have shown does not predictably correlate diversity. This difference suggests led formation areas Balkans: through combination dispersal speciation local radiation south-east, respectively. calls caution strategies relying solely number may change view priorities this region.