Watersheds and sub-basins of Mongolia. Gray dots represent all sampling points of dytiscids. Abbreviations: KZ – Kazakhstan; WS – West Siberia; ES – East Siberia; FE – Far East; MAN – Manchuria; NMO – Nei Mongol; GAN – Gansu; XIN – Xinjiang; AOB–Arctic Ocean Basin; POB – Pacific Ocean Basin; CAIB – Central Asian Inland Basin.