Sphaerodactylus ariasae, the Jaragua sphaero or dwarf gecko, is a very small Gekkonidae species in the Sphaerodactylus genus. It is one of the world's two smallest known reptiles (the other is the S. parthenopion, native to the British Virgin Islands). The Jaragua sphaero measures 16–18 mm from the snout to the base of the tail and can fit on a US 25-cent coin.