Cryptic freshwater species contribute to biodiversity, but their community integration remains unclear. In a recent study published in Freshwater Biology, we examined local and regional co-occurrences of cryptic amphipod species to understand the role of phylogenetic relationships in shaping biodiversity patterns. Our findings suggest that regional overlap results from dispersal rather than phylogenetic relatedness, with sympatries occurring more frequently among species from different clades. Ultimately, spatial patterns reflect historical events like mountain formation and climatic shifts, influencing biodiversity at local and regional scales.