Abstract
The Ryukyu Archipelago accommodates 52 native species/subspecies (26 genera belonging to ten families) of terrestrial reptiles and 22 native species/subspecies (ten genera belonging to six families) of amphibians. This paper reviews the geographic similarity and diversity patterns of the current herpetofauna of the Ryukyus and adjacent regions, and discusses factors influencing the formation of it in this archipelago. Cluster analyses of similarity indices for both reptiles and amphibians indicate that the Ryukyu herpetofauna is strongly influenced by geohistory of this archipelago involving long isolation especially in its north-central part (i.e., southern Tokara, Amami, and Okinawa Groups). Correlation analyses suggest that the faunal diversity on each island is significantly influenced by its habitat diversity as reflected by the island area (for reptiles) or height (amphibians).