Snake diversity of the Aralo-Caspian basin

Snake diversity of the Aralo-Caspian basin includes 61 species in 8 families and is composed by local faunas of the Northern Caspian depression, Greater Caucasus and Ciscaucasia, Lesser Caucasus and Transcaucasia, Alborz and Turkmeno-Khorasanian mountains, Aralo-Caspian isthmus, deserts and mountains of the Middle Asia and plains of the Aral Sea region. Regions with richest snake diversity are Alborz, Turkmeno-Khorasanian mountains and Transcaucasia. Δ-diversity grows in the latitudinal direction, from the plains of the Aral Sea region and the North Caspian lowland to the mountain systems of the Iranian plateau. Level of species endemism is 23%. Six of the fourteen endemics live in the Alborz mountains.